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GemmologyThe Journal of Volume 35 / No. 1 / 2016

The Gemmological Association of Great Britain Save the date Gem-A Conference

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The Gemmological Association of Great Britain, 21 Ely Place, London, EC1N 6TD, UK. T: +44 (0)20 7404 3334 F: +44 (0)20 7404 8843. Registered charity no. 1109555. A company limited by guarantee and registered in No. 1945780. Registered Office: 3rd Floor, 1-4 Argyll Street, London W1F 7LD.

Conference_03-2016_March-April_Save The Date_A4.indd 1 12/04/2016 10:44:17 Contents GemmologyThe Journal of Volume 35 / No. 1 / 2016

COLUMNS p. 22 1 What’s New DiamondDect for identification|Triple D photo kit|Upgraded Diamond- View|Variofoc LED lighting system|AGTA Tucson seminars| Responsible sourcing of coloured stones report|World Council report|GSJ 2015 Annual Meeting abstracts|ICGL Newsletter|Large CVD synthetic diamond seen p. 64 by HRD Antwerp|MAGI diamond type report|SSEF Facette|Updated Journal cumulative index|Wyoming report|GemeSquare app and GemePrice 5.0|Historical reading lists|Hyperion inclusion search engine|Gems from the French Jewels exhibit ARTICLES 6 Gem Notes Apatite from Iran|Purple apa- Feature Articles tite from Namibia| from Madagascar| 28 Characterization of Oriented Inclusions in Cat’s-eye, and pyrite mixture from Co- Star and Other lombia| from Mahenge, By Karl Schmetzer, Heinz-Jürgen Bernhardt and H. Albert Gilg Tanzania|Grandidierite from Madagascar|Lalique pen- dant in polarized light|Faceted 56 The Great Mughal and the Orlov: One and the Same quartz with petroleum inclu- Diamond? sions from |Quartz slabs By Anna Malecka from Inner Mongolia|Sphalerite inclusions in quartz| from Gemmological Brief Liberia|Unstable yellow colour in |Petroleum inclusion 64 A Lead-Glass-Filled Doublet in pink |Spurrite from New By Supparat Promwongnan, Thanong Leelawatanasuk and Mexico, USA| mining at Saengthip Saengbuangamlam the Scorpion mine, Kenya|Mussel from the Philippines 70 Conferences Accredited Gemologists Association| Industry & Laboratory Cover Photo: Cat’s-eye chrysoberyls are Conference|Jewelry Industry Summit shown here in a gold (11.71 ct oval), as loose round (11.00 75 Gem-A Notices and 14.09 ct) and mounted in gold (6.48–8.89 ct). Courtesy of The 78 Learning Opportunities Edward Arthur Metzger Gem Collection at the Heasley , Cornell 82 New Media University, Ithaca, New York, USA; composite photo by Jeff Scovil. 86 Literature of Interest

The Journal is published by Gem-A in collaboration with SSEF and with the support of AGL and GIT.

ISSN: 1355-4565, http://dx.doi.org/10.15506/JoG.2016.35.1 i The Journal of emmology G THE GEMMOLOGICAL ASSOCIATION OF GREAT BRITAIN Editor-in-Chief Production Editor Marketing Consultant Brendan M. Laurs Mary A. Burland Ya’akov Almor [email protected] [email protected] [email protected] 21 Ely Place Editorial Assistant Editor Emeritus Assistant Editor London EC1N 6TD Carol M. Stockton Roger R. Harding Michael J. O’Donoghue UK Associate Editors t: +44 (0)20 7404 3334 Edward Boehm, RareSource, Chattanooga, Tennessee, USA; Alan T. Collins, King’s College f: +44 (0)20 7404 8843 London; John L. Emmett, Chemistry, Brush Prairie, Washington, USA; Emmanuel e: [email protected] Fritsch, University of Nantes, France; Rui Galopim de Carvalho, Portugal Gemas, Lisbon, w: www.gem-a.com Portugal; Lee A. Groat, University of British Columbia, Vancouver, Canada; Thomas Hainschwang, GGTL Laboratories, Balzers, Liechtenstein; Henry A. Hänni, GemExpert, Registered Charity No. 1109555 Basel, Switzerland; Jeff W. Harris, University of Glasgow; Alan D. Hart, The Natural History Registered office: House, Museum, London; Ulrich Henn, German Gemmological Association, Idar-Oberstein; Jaroslav 1–4 Argyll Street, London W1F 7LD Hyršl, Prague, Czech Republic; Brian Jackson, National , Edinburgh; Stefanos Karampelas, GRS Gemresearch Swisslab, Lucerne, Switzerland; Lore Kiefert, Gübelin Gem Lab Ltd., Lucerne, Switzerland; Hiroshi Kitawaki, Central Gem Laboratory, Tokyo, Japan; Michael S. Krzemnicki, Swiss Gemmological Institute SSEF, Basel; Shane F. McClure, Gemological Institute of America, Carlsbad, California; Jack M. Ogden, Striptwist President Ltd., London; Federico Pezzotta, Natural History Museum of Milan, Italy; Jeffrey E. Post, Harry Levy Smithsonian Institution, Washington DC, USA; Andrew H. Rankin, Kingston University, Surrey; George R. Rossman, California Institute of Technology, Pasadena, USA; Karl Vice Presidents Schmetzer, Petershausen, Germany; Dietmar Schwarz, AIGS Lab Co. Ltd., Bangkok, Thailand; David J. Callaghan, Alan T. Collins, Menahem Sevdermish, GemeWizard Ltd., Ramat Gan, Israel; Guanghai Shi, China University Noel W. Deeks, E. Alan Jobbins, of Geosciences, Beijing; James E. Shigley, Gemological Institute of America, Carlsbad, Michael J. O’Donoghue, California; Christopher P. Smith, American Gemological Laboratories Inc., New York, New Andrew H. Rankin York; Evelyne Stern, London; Elisabeth Strack, Gemmologisches Institut Hamburg, Germany; Tay Thye Sun, Far East Gemological Laboratory, Singapore; Pornsawat Wathanakul, Gem Honorary Fellows and Jewelry Institute of Thailand, Bangkok; Chris M. Welbourn, Reading, Berkshire; Joanna Gaetano Cavalieri, Terrence Whalley, Victoria and Albert Museum, London; Bert Willems, Leica Microsystems, Wetzlar, S. Coldham, Emmanuel Fritsch Germany; Bear Williams, Stone Group Laboratories LLC, Jefferson City, Missouri, USA; J.C. (Hanco) Zwaan, National Museum of Natural History ‘Naturalis’, Leiden, The Netherlands. Honorary Diamond Member Martin Rapaport Content Submission The Editor-in-Chief is glad to consider original articles, news items, conference/excursion Honorary Life Members reports, announcements and calendar entries on subjects of gemmological interest for Anthony J. Allnutt, Hermann Bank, publication in The Journal of Gemmology. A guide to the various sections and the preparation Mary A. Burland, Terence M.J. Davidson, of manuscripts is given at www.gem-a.com/publications/journal-of-gemmology/submit- Peter R. Dwyer-Hickey, Gwyn M. Green, an-article.aspx, or contact the Production Editor. Roger R. Harding, John S. Harris, Subscriptions J. Alan W. Hodgkinson, John I. Koivula, Gem-A members receive The Journal as part of their membership package, full details of Jack M. Ogden, C.M. (Mimi) Ou Yang, which are given at www.gem-a.com/membership.aspx. Laboratories, libraries, museums and Evelyne Stern, Ian Thomson, Vivian P. similar institutions may become Direct Subscribers to The Journal (see www.gem-a.com/ Watson, Colin H. Winter publications/subscribe.aspx). Interim Chief Executive Officer Advertising Nicholas H. Jones Enquiries about advertising in The Journal should be directed to the Marketing Consultant. For more information, see www.gem-a.com/publications/journal-of-gemmology/advertising- Council in-the-journal.aspx. Miranda E.J. Wells – Chair Kathryn L. Bonanno, Mary A. Burland, Database Coverage Justine L. Carmody, Paul F. Greer, Kerry The Journal of Gemmology is covered by the following abstracting and indexing services: H. Gregory, J. Alan W. Hodgkinson, Australian Research Council academic journal list, British Library Document Nigel B. Israel, Jack M. Ogden, Richard Supply Service, Chemical Abstracts (CA Plus), Copyright Clearance Center’s M. Slater, Christopher P. Smith RightFind application, CrossRef, EBSCO (Academic Search International, Discovery Service and TOC Premier), Gale/Cengage Learning Academic Branch Chairmen OneFile, GeoRef, Mineralogical Abstracts, ProQuest, Scopus and the Thomson Midlands – Georgina E. Kettle Reuters’ Emerging Sources Citation Index (in the Web of Science). North East – Mark W. Houghton South East – Veronica Wetten Copyright and Reprint Permission South West – Richard M. Slater Full details of copyright and reprint permission are given on The Journal’s website. The Journal of Gemmology is published quarterly by Gem-A, The Gemmological Association of Great Britain. Any opinions expressed in The Journal are understood to be the views of the contributors and not necessarily of the publisher. Printed by DG3 () Ltd. ™ © 2016 The Gemmological Association of Great Britain Understanding Gems ISSN: 1355-4565 Cert no. TT-COC-002454

ii The Journal of Gemmology, 35(1), 2016 What’s New

INSTRUMENTS AND TECHNIQUES

DiamondDect Diamond Identification Instrument Upgraded DiamondView Instrument TaiDiam Technology Co. Ltd. (Zhengzhou, China) an- In June 2015, the De Beers Group of Companies nounced in September 2015 the availability of the released through its International Institute of DiamondDect portable diamond identification instru- Diamond Grading & Research an enhanced version ment from its associated company Krisdiam. Weigh- of the DiamondView. The upgraded instrument ing approximately 8 kg, the instrument includes a produces a surface image that polariscope, microscope, fibre-optic illuminator and provides information on a sample’s growth history more, plus a Windows- that is useful for separating natural from synthetic based computer tablet . The upgraded model has changeable equipped with iden- filters that are useful tification software to for enhancing features separate CVD and shown by some synthetic HPHT synthetics from diamonds, particularly natural diamonds. Ac- the latest-generation cording to TaiDiam, the CVD products that show instrument can ana- blue fluorescence. The lyse colourless to near- instrument is available in a standard magnification colourless diamonds model for stones weighing 0.05–10 ct, and in a from 0.01 ct (loose) or 0.03 ct (mounted) up to 10 high-magnification version for melee-sized goods ct. For additional information, visit http://en.taidiam. of 0.01–0.20 ct. A new adapter for the vacuum com/news_detail/newsId=61.html. A user manual stone holder allows for the examination of some with helpful information on separating natural from items such as stud and simple synthetic diamonds is available at http://en.taidiam. rings. For more information, visit www.iidgr.com/ com/download_detail/&downloadsId=19.html. en/instruments/diamondview. BML CMS Variofoc LED Lighting System Triple D Photo Kit In March 2015, System Eickhorst released the In February 2015, Triple Variofoc LED incident lighting system, which features D Experience Ltd. in Is- a series of interchangeable LED heads designed for rael launched a Photo Kit use in a double-gooseneck for gem photography that lamp unit. Three types of LED works with a smartphone. heads are available: spot, flood The kit consists of a port- and diffuse, each in colour able, compact unit that temperatures of neutral white includes a stone holder, (6,000 K) or daylight (4,000 light source, background and magnifier that cradles K). Another interchangeable a smartphone, enabling the user to take a high- LED head provides long-wave quality photo or video of a gemstone. The accompa- UV illumination (366 nm). nying free smartphone app (for iPhone and Android) A variety of mountings are enables the user to enter stone data and an iden- available, including a foot tification report, send information to clients, com- plate that allows the unit to be used in conjunction municate via live chat, and store information for with a gemmological microscope. Visit www.eickhorst. ease of access. To learn more, visit http://tripled- com/en/lamps-lighting/desktop-lights/variofoc-led/ experience.com. CMS merkmale. BML

What’s New 1 What’s New

NEWS AND PUBLICATIONS

AGTA GemFair Tucson Seminars half. Fourth-quarter growth The American Gem Trade Association hosted an was driven by central banks array of seminars 3–6 February 2016 in Tucson, and investment, offset by Arizona, USA. The seminars a marginal contraction in covered various aspects jewellery and continued of gem mining, marketing, declines in technology. Sup- industry, identification and ply remained constrained: jewellery by presenters from Annual mine production in- around the world. A flash creased by the slowest rate drive containing recordings since 2008 (+1%) and recy- of 27 of the seminars can cling dropped to multi-year be purchased for US$50.00 lows. Total supply declined for non-AGTA members (AGTA members have access 4% to 4,258 tonnes, the lowest since 2009. CMS through the AGTA eLearning online program). Visit www.agta.org/education/seminars.html for the order form, as well as a summary of the presentations and GSJ 2015 Annual Meeting Abstracts speakers. CMS Abstracts of papers presented at the 2015 Annual Meeting of the Gemmological Society of Japan are available at www.jstage.jst.go.jp/browse/gsj. Environmental and Social Responsibility for The abstracts are written in Japanese with a brief Coloured Stones English summary provided. Abstracts from prior GSJ The Responsible Ecosystems Sourcing Platform re- conferences dating back to 2001 are also available. leased an International Working Group report on 29 January 2016 titled ‘Chal- lenges to Advancing Environ- mental and Social Responsi- CMS bility in the Coloured Gems Industry’. Among the 10 major challenges discussed ICGL Newsletter are the importance of tailor- The Winter 2015 issue of the ing socioeconomic solutions International Consortium of to the unique needs of each Gem-Testing Laboratories geopolitical venue and the Newsletter is now available lack of basic awareness of at http://icglabs.org. Topics environmental principles. For a summary descrip- include use of a multi-spec- tion and a link to the full report, visit http://tinyurl. tral induced luminescence com/gopvosp. CMS imaging system for screen- ing of near-colourless HPHT synthetic diamond melee Gold Demand Trends 2015 in China, identification of dyed golden South Sea The World Gold Council released its annual report in cultured pearls and examination of a treated blue February 2016, with a summary web page at www. diamond. CMS gold.org/supply-and-demand/gold-demand-trends, where the full report, press report and statistics can be downloaded. Gold demand in the fourth quarter Large CVD synthetic diamond seen by increased to a 10-quarter high of 1,117.7 tonnes. HRD Antwerp Full-year demand was virtually unchanged, with weak- On 28 September 2015, HRD Antwerp posted an ness in the first half offset by strength in the second article by Ellen Barrie and Ellen Biermans titled

2 The Journal of Gemmology, 35(1), 2016 What’s New

‘HRD Antwerp Recently ral diamonds found in a parcel of HPHT synthetic Examined a 3.09 ct CVD diamonds; analysis of melee-size diamonds and Lab-Grown Diamond’ at small baguettes with the Lumos micro-FTIR spec- www.hrdantwerp.com/ trometer; updates concerning the ASDI instrument en/news/hrd-antwerp-re- for analysing melee-size diamonds; analysis cently-examined-a-309-ct- with X-ray phase contrast and scattering imaging; cvd-lab-grown-diamon. pearl structures visualized by neutron scattering; The report contains a ‘ageing’ treatment of pearls; a ‘historic’ neck- thorough description of lace containing cultured pearls; carbon-14 dating the large CVD synthetic, including photomicrographs, of pearls from a shipwreck; several exceptional DiamondView images, and both UV-Vis and photo- items sold at auction by Christie’s and Sotheby’s luminescence spectra. CMS in 2014–2015; examination of iconic from Mozambique; conference reports; recaps of SSEF courses, instrumentation and published research; MAGI Application Note on Diamond Type and more. BML The M&A Gemological Instru- ments website posted ‘Appli- cation Note: Diamond classi- Updated Cumulative Index for fication – the diamond types’, The Journal of Gemmology by Alberto Scarani and Mikko In February 2016, Gem-A Astrom, on 29 January 2016. released the first update of It provides a summary of dia- The Journal’s cumulative mond types and impurities as index, covering all issues background to a discussion from 1947 to 2015 of FTIR spectroscopy and MAGI’s GemmoFtir Diamond (Volumes 1–34). The con- Type Analysis software. To download the report, visit tents are listed by subject, www.gemmoraman.com/Articles//DiamondTyping. but the PDF also can aspx. CMS be searched for specific authors as well as topics. The cumulative index is SSEF Facette available only in electronic The Swiss Gemmological Institute SSEF has re- format for free download from The Journal’s leased the latest issue of Facette Magazine (No. website at www.gem-a.com/publications/journal- 22, February 2016), which is available at www. of-gemmology/indexes.aspx. CMS ssef.ch/research-publications/facette. It de- scribes: SSEF’s new labo- ratory in Basel; SSEF’s Wyoming Revisited criteria for colour terms In mid-December 2015, ‘pigeon blood red’ and Palagems.com posted an ‘royal blue’; rubies from article by the late Roger Mozambique (including Merk FGA, titled ‘Wyoming their low-temperature treat- jades revisited’ at http://m. ment) and Madagascar palagems.com/wyoming- (Andilamena); jades-revisited. The article is from Madagascar (Andra- a personal look at the history nondambo), Nigeria and and types of from Thailand (Kanchanaburi); Wyoming, USA, with photos of some exceptional REE in danburite; heat treatment of spinel from examples of rough, sliced and fashioned specimens Mahenge, Tanzania; cobalt diffusion-treated spi- that illustrate the range of colours, textures and nel; a challenging Ramaura synthetic ruby; natu- exterior appearances. CMS

What’s New 3 What’s New

OTHER RESOURCES

GemeSquare App and GemePrice5.0 tions of the references cited, along with informa- Released in January 2016 by GemeWizard Inc. tion about where to locate the articles. To peruse (Ramat Gan, Israel), the GemeSquare smartphone these lists, visit www.gia.edu/library and click on app is a free colour communication system that the links under ‘Recommended Reading & Biblio- allows users to precisely define and describe a graphies’. CMS particular colour; both iOS and Android devices are supported. In February 2016, GemeWizard Hyperion Inclusion Search Engine released GemePrice5.0, the most recent edition of In December 2015, Lotus Co. Ltd. this online wholesale pricing system for diamonds, (Bangkok, Thailand) launched Hyperion, an online coloured stones and jewellery. New to this version photographic library of gem are 10 gem varieties that display different textures inclusions. It includes a or optical effects, including , , search feature that enables and . The system is available only the user to look for images to gem-industry professionals through subscription based on gem type, origin, at www.gemewizard.com/store-price.php. CMS enhancement and/or key- word. Gem types include natural and synthetic ruby, sapphire and spinel. Origins include 31 countries and five types of synthetics. Under enhancement, the options are ‘none’ plus 10 treatment choices. Also available is a useful listing of selected literature on gem inclusions. Use of the service is free at www.lotusgemology.com/ index.php/library/inclusion-gallery, but note that the images are copyrighted. CMS

MISCELLANEOUS

Historical Reading Lists from the GIA Library Gems from the French The Richard T. Liddicoat Gemological Library at the The MINES ParisTech Gemological Institute of Museum America (Carlsbad, Cali- opened a new per- fornia, USA) recently post- manent exhibit on 5 ed four Historical Reading January 2016 featur- lists online: ‘Diamonds in ing emerald, pink to- Arkansas’, ‘The Koh-i-noor paz and from the French Crown Jewels, Diamond’, ‘Pearls from including gems from the ornaments of Empress India’ and ‘Ruby Mines of Marie-Louise (1791–1847) and the Imperial Crown Burma’. Prepared by Dr of Napoléon III (1808–1873). Details are posted at James Shigley, each list www.musee.mines-paristech.fr/Our-Collections/ includes brief descrip- Exhibits/CrownJewels. CMS

What’s New provides announcements of new instruments/technology, publications, online resources and more. Inclusion in What’s New does not imply recommendation or endorsement by Gem-A. Entries are prepared by Carol M. Stockton (CMS) or Brendan M. Laurs (BML), unless otherwise noted.

4 The Journal of Gemmology, 35(1), 2016 Pink Apatite with Muscovite on Albite Shah Nassir Peak, Gilgit, Pakistan

Coming Soon: The Sisk Gemology Reference by Jerry Sisk

• jtv.com Gem Notes

COLOURED STONES

Apatite from Hormuz Island, Iran During the past two decades, small quantities of gem-quality apatite have been gathered by local enthusiasts on Iran’s Hormuz Island in the Persian Gulf. The gems are formed in joints and fractures contained within -goethite ores that are associated with deeply altered igneous rocks of variable composition ranging from dacite- to quartz diorite (Elyasi et al., 1977). The apatite is thought to have a hydrothermal or igin (Padyar et al., 2012). Weathering of the host rocks has dispersed the apatite in areas associated with ochre-coloured soil and salt deposits (Figure 1). The apatite is found as broken pieces and euhedral , Figure 1: Apatite from Hormuz Island, Iran, is found typically up to 2–3 cm long, that are somewhat dispersed over the ground from weathering of associated fractured. The gem-quality material is transparent iron-rich ores. Photo by B. Rahimzadeh. to translucent, and generally ranges from yellow Recently, apatite from Hormuz Island was to greenish yellow (Figure 2); less commonly characterized by these authors for this report. The it is green or orangey yellow. It shows various samples consisted of one , three faceted degrees of colour saturation, from very pale to stones and two freeform carvings weighing 2–4 strong. Some samples show colour zoning, with ct (e.g. Figure 3). They were greenish yellow to yellower cores and greener outer portions. green, and RI readings ranged from 1.625 to 1.640 (with small values) for the faceted Figure 2: These broken pieces and crystal fragments of stones and were 1.64 (spot readings) for the apatite from Hormuz Island show a light yellow colour other samples. An RI of 1.625 is somewhat low with various degrees of iron staining. The coin is 3 cm in for apatite, but the higher measurements were diameter. Photo by B. Rahimzadeh. consistent with reported values (1.63–1.64, cf. O’Donoghue, 2006). The hydrostatic SG values were 3.13–3.17, which is somewhat low for apatite (3.17–3.23, cf. O’Donoghue, 2006). The greener samples showed higher SG and lower RI measurements. All of the stones were inert to long- and short-wave UV radiation. Microscopic examination revealed small euhedral hematite inclusions and conchoidal fractures in some samples that were locally iron stained. Hormuz Island apatite may have significant potential for the gem industry if systematic exploration is undertaken and appropriate methods for cutting and polishing the stone are introduced into the local market. Another source

6 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 3: The Hormuz Island apatite samples studied for this report included these slightly greenish yellow cabochons (left, ~4 ct each) and yellow faceted stones (right, ~2–4 ct). Photos by B. Rahimzadeh. of apatite (some of which is gem quality) is the Proceedings of the Second Geological Symposium Sfordi mine in central Iran, where the crystals are of Iran, The Iranian Petroleum Institute, Tehran, hosted by iron- deposits related to alkaline Iran, 31–72 [in Persian]. O’Donoghue M., Ed., 2006. Gems: Their Sources, igneous rocks (syenite). Descriptions and Identification, 6th edn. Dr Bahman Rahimzadeh ([email protected]) Butterworth-Heinemann, Oxford, 873 pp. and Rasoul Sheakhy Qeshlaqi Padyar F., Borna B., Qurbani V., Alizadeh V. and Shahid Beheshti University, Tehran, Iran Jafarzadeh N., 2012. Study of fluid inclusions and Raman microspectrometry of Hormuz Island References apatites. The 13th Conference of Geosciences, Elyasi J., Aminsobhani E., Behzad A., Moiinvaziri H. Geological Survey and Mineral Exploration of and Meisami A., 1977. Geology of Hormuz Island. Iran, Tehran, 13–16 February, 6 pp.

Purple Apatite from Namibia

Gem-quality apatite is rarely produced from found that showed a superb colour Namibia, and an interesting yellow chatoyant (e.g. Figure 4) and relatively good . Individual stone was documented fairly recently by one of crystals measured from 1 × ½ cm up to 8 × 6 cm, these authors (Johnston, 2014). During the past and some were found on a matrix of transparent few years, apatite in various other colours— quartz crystals. In addition to purple, the apatite including deep purple—also was produced colours included white, colourless, pink, green- in Namibia. From late 2012 to 2014, one of the grey and dark green. The area was reclaimed in authors’ (CLJ) suppliers reported small 2014, and no additional apatite mining has been amounts of purple apatite on Farm Okatjimukuju, allowed by the property owner. located approximately 20 km south-east of Karibib. Some of this purple apatite appeared at the The apatite-bearing pockets were associated with September 2015 Hong Kong gem show, and quartz, albite and muscovite. The initial finds additional material was brought to the October consisted of moderately purple apatite crystals 2015 Munich show. One of these authors (JJB) with a white/green core, but unfortunately the vast acquired 500 g of the rough material, which majority of the material was recovered as broken proved challenging to work with due to abundant pieces that were not transparent. Additional mining fractures that required clipping with and produced a few dark purple apatites consisting of some grinding on the cutting wheel to see inside. well-formed doubly terminated hexagonal prisms After this process, only ~100 g of preformed pieces (some on matrix). Shortly before mining ceased, remained that were somewhat clean. Author JJB approximately 20–30 much better specimens were faceted ~20 stones that ranged from light lavender

Gem Notes 7 Gem Notes

Figure 5: Weighing 7.27 ct, this eye-clean cushion brilliant is unusually large for purple apatite from Namibia. Photo by Jeff Scovil.

cushion (Figure 5). In addition, a parcel of small- sized material is being cut overseas. The purple colour of this apatite is reminiscent of the classic material produced from the Pulsifer Quarry in Maine, USA (e.g. Manchester and Bather, 1918). Christopher L. Johnston ([email protected]) Omaruru, Namibia John J. Bradshaw Coast-to-Coast Rare Stones Figure 4: Deep purple apatite is associated with quartz and Nashua, New Hampshire, USA albite on this specimen (14 × 13 cm) from the Karibib area of Namibia. Specimen and photo courtesy of Hans Soltau. References Johnston C.L., 2014. Gem Notes: Cat’s-eye apatite to deep purple; some of them had a slight grey from Namibia. Journal of Gemmology, 34(3), overtone. So far, most of the gems weigh <2 ct 191. Manchester J.G. and Bather W.T., 1918. Famous (eye clean to very slightly included), and only four mineral localities: Mt. , Mt. Apatite and other eye-clean stones weighing >3 ct have been cut, localities in Maine. American Mineralogist, 3, including a top-colour 3.51 ct oval and a 7.27 ct 169–174.

Orange-Red to Yellowish Brown Cordierite from Madagascar

Gem-quality cordierite is typically seen as blue of the authors (FP) obtained about 120 kg of material (iolite), showing strong in rough material of mixed quality from the miners yellow, light blue and dark violet-blue. However, over a period of a few months, from which only a in late 2014 one of the authors (FP) learned about few kilograms were suitable for cutting cabochons a new occurrence of a much different cordierite, and faceted stones (e.g. Figures 6 and 7). which typically ranged from dark orange-red to Three faceted stones weighing 2.55, 3.17 and yellowish brown. The material is recovered by 3.63 ct were characterized for this report (Figure 7). local miners from weathered residual deposits in They displayed strong pleochroism, in (1) strong southern Madagascar, probably in the Gogogogo orange, (2) greyish purplish (red-) pink and (3) area, north of Ampanihy in Tuléar Province. One slightly brownish (‘straw’) yellow. The pleochroism

8 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 6: Cabochons cut from the new Madagascar cordierite show unusual orange-red to yellowish brown coloration. The total weight of the stones shown here is 45.18 ct. Photo by F. Pezzotta.

could clearly be observed with the naked eye, and minute, parallel-oriented needles and small resulting in an overall dark, slightly brownish platelets, possibly . Tiny fractures were seen orange-red or yellowish brown depending on the along partially healed fissures and also adjacent viewing angle. RI values varied between 1.530 and to various mineral inclusions. Chemical analyses

1.540, with nα = 1.530, nβ = 1.533–1.534 and nγ = of the three samples by energy-dispersive X-ray 1.540, yielding a birefringence of 0.010. The optic fluorescence (EDXRF) spectroscopy showed major sign was consistently biaxial positive, which differs amounts of Mg, Al and Si, minor amounts of Fe, from the common blue iolite (biaxial negative). and traces of Mn. Energy-dispersive spectroscopy Hydrostatic SG values were 2.53–2.55; these are on a slab of the cordierite by author GRR using at the low end of the known range for cordierite a scanning electron microscope showed similar (2.53–2.78, cf. Deer et al., 1986). All samples were composition. The optical spectrum showed features inert to long- and short-wave UV radiation. The of Fe2+ found in blue cordierite, plus water-related stones were moderately included, mostly with absorptions in the near-infrared, but also a strong partially healed fissures but also with irregularly absorption near 500 nm that is the cause of shaped, breadcrumb-like inclusions and various the unusual orange-red to yellowish brown colour. mineral inclusions. Raman microspectroscopy Further information on this new cordierite will using a Thermo DXR Raman microscope with be reported in a future publication. 532 nm excitation identified the inclusions Dr J. C. (Hanco) Zwaan ([email protected]) as follows: rounded and elongated—or thin, long Netherlands Gemmological Laboratory prismatic—crystals of ; blocky and small National Museum of Natural History ‘Naturalis’ rectangular-appearing grains of quartz; rounded Leiden, The Netherlands crystals of apatite; a small platelet of phlogopite; Dr Federico Pezzotta Figure 7: These three Madagascar (2.55–3.63 ct) Natural History Museum of Milan, Italy were analysed for this report. Photo by J. C. Zwaan. Dr George R. Rossman California Institute of Technology Pasadena, California, USA

Reference Deer W.A., Howie R.A. and Zussman J., 1986. - Forming —Disilicates and Ring Silicates, Vol. 1B, 2nd edn. Longman, New York, 629 pp.

Gem Notes 9 Gem Notes

An Unusual Emerald and Pyrite Mixture from Colombia

Emeralds from Colombia are commonly associated Overall, the polish lustre of the cabochons was with pyrite (for information on the geology of mediocre due to the different hardness of the three the deposits see, e.g., Pignatelli et al., 2015), and minerals (Mohs 7½–8 for , 6–6½ for pyrite, 3½ sometimes pyrite is found also as inclusions in the for ). Within the mixed emerald-dolomite . In 2015, a new find of emerald from areas, the softer grains of dolomite could be an undisclosed locality in Colombia produced easily distinguished with a loupe from the harder intergrowths of pyrite, emerald and dolomite. emerald by differences in their lustre. Cabochons cut from this material are quite Pyrite is a relatively unstable mineral, especially distinctive, and four of them were studied for this in humid conditions, and it is very fragile. For this report (e.g. Figure 8). reason, the studied cabochons are not suitable The ratio of pyrite, emerald and dolomite for jewellery use, but they represent interesting in the samples was highly variable. In two of collector’s objects. them, pyrite clearly crystallized first, forming Dr Jaroslav Hyršl ([email protected]) euhedral cubic crystals up to 10 mm. In the other Prague, Czech Republic two cabochons, pyrite was present as irregular corroded masses surrounding small grains of Reference emerald (e.g. Figure 9). The green areas of the Pignatelli I., Giuliani G., Ohnenstetter D., Agrosì G., stones were typically formed by a granular Mathieu S., Morlot C. and Branquet Y., 2015. Col- ombian trapiche emeralds: Recent advances in mixture of emerald and dolomite (again, see understanding their formation. Gems & Gemology, Figure 9)—except for the marquise-shaped 51(3), 222–259, http://dx.doi.org/10.5741/gems. cabochon, in which both minerals occurred 51.3.222. separately. (The presence of emerald and dolomite in the cabochons was confirmed by Figure 9: The texture of the various minerals is visible on the Raman spectroscopy; pyrite does not produce a base of this cabochon (35 mm long), which shows irregular Raman spectrum with this author’s unit.) corroded masses of pyrite and granular intergrowths of emerald and dolomite. Photo by J. Hyršl. Figure 8: These cabochons from Colombia consist of intergrowths of pyrite, emerald and dolomite. The centre stone is 36 mm long. Photo by J. Hyršl.

Garnet from Mahenge, Tanzania The Mahenge area in the Morogoro region of pink from a new find in this area that south-central Tanzania is a well-known source he sold as ‘Mahenge Malaya’. He obtained the of several gem varieties, particularly spinel rough material in mid-December 2015 in Arusha, and ruby. During the 2016 Tucson gem shows, Tanzania. Consisting of clean alluvial pebbles, the Steve Ulatowski (New Era Gems, Grass Valley, garnet ranged from pinkish orange to a saturated California, USA) had some pink to orangey ‘hot’ pink. Most of the production was rather

10 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 10: Weighing 6.79 and 6.84 ct, these faceted garnets from Mahenge, Tanzania, are unusually large for this new find. Courtesy of Evan Caplan; photo by Jeff Scovil.

small sized, although Ulatowski encountered ~1 between crossed polarizers, and the garnet was kg of material consisting of >0.5 g stones, with inert to both long- and short-wave UV excitation. the largest pieces weighing >3 g. Faceting of two Magnetic susceptibility was not insignificant, of the largest pieces yielded attractive pink and with it being picked up by a 9-mm-diameter pinkish orange weighing 6.79 and N-52 REE magnet, and easily dragged by smaller 6.84 ct (Figure 10). N-52 magnets. The stone appeared eye clean, but Ulatowski loaned a 3.22 ct triangular preform microscopic observation revealed several small, for examination, and the table facet was kindly scattered, whitish, breadcrumb-like inclusions polished during the show by Todd Wacks (Tucson as well as what appeared to be fine strings of Todd’s Gems, Tucson, Arizona). Its colour was partially dissolved needles. ‘fleshy’ pink with a faint brown tint (World of Pink is one of the rarer colours of garnet, and Color 2.5R5/6, Brownish Red) under daylight- is typically seen in either the hydrogrossular or equivalent lighting. Viewed with incandescent -dominant varieties. EDXRF chemical lighting, the brown tint was not evident and analyses with an Amptek X123-SDD spectrometer the stone appeared slightly more reddish pink revealed major amounts of Mn and Fe, minor (World of Color 2.5R5/10, Moderate Red). This Ca, and traces of Cr. Although Mg was below colour behaviour is typical of many so-called accurate detection levels for this instrument, Malaya or colour-shift garnets from East Africa. electron microprobe analysis of five samples of The stone had an RI of 1.751 and a hydrostatic this garnet by John Attard (Attard’s Minerals, San SG of 3.82. Anomalous extinction was observed Diego, California, USA) revealed major amounts of Mg in all of them. They consisted mainly of Figure 11: The visible-range spectrum of a ‘fleshy’ pink pyrope with variable and , sample of Mahenge garnet showed absorptions related to and a very minor component. both almandine and spessartine. Visible-range spectroscopy using an Ocean Visible Absorption Spectrum Optics USB4000 spectrometer with a 7-inch 410 integrating sphere showed weak almandine 1.5 423 absorptions at 503, 522 and 573 nm, as well 430 as spessartine absorptions at 410, 423 and 430 1.0 503 nm (Figure 11). Infrared spectroscopy with a 522 573 Absorbance PerkinElmer Spectrum100 Fourier-transform 0.5 infrared (FTIR) instrument revealed a significant water content. The various water-related peaks −1 400 450 500 550 600 650 700 between 3560 and 3675 cm were consistent Wavelength (nm) with OH absorption (Ogasawara et al., 2013).

Gem Notes 11 Gem Notes

This attractively coloured garnet is a welcome Reference addition to the gem marketplace. Ogasawara Y., Sakamaki K. and Sato Y., 2013. Water contents of garnets from the Garnet Ridge, Cara Williams FGA and Bear Williams FGA northern Arizona: H2O behavior underneath the ([email protected]) Colorado Plateau. American Geophysical Union, Stone Group Laboratories Fall Meeting, abstract #V23A-2754, http://adsabs. Jefferson City, Missouri, USA harvard.edu/abs/2013AGUFM.V23A2754O.

New Production of Grandidierite from Madagascar

2+ 3+ Grandidierite, (Mg, Fe ) (AlFe )3(SiO4)(BO3)O2, is larger fractured pieces weighing 5–10 g. The colour an extremely rare collector’s stone that is known ranged from pale to moderately saturated greenish in gem quality mainly from Madagascar, and less blue to bluish green, in medium to dark tones. commonly from . The material from Gautier faceted 40 clean stones weighing 0.10–1.78 Madagascar typically lacks transparency: Ostwald ct (e.g. Figure 12). Gemmological properties of a (1964) noted that “only massive [rough] material recently produced Malagasy grandidierite were de- was available for study”, and Mitchell (1977) scribed by Vertreist et al. (2015). stated that the small number of faceted stones and This new production from Madagascar marks cabochons that he examined were “semitransparent, the first time that a significant number of clean due to fissures and inclusions”. Schmetzer et al. faceted grandidierites have become available, and (2003) documented the first transparent faceted also the largest pieces of transparent material ever grandidierite (0.29 ct); it was also the first time this to be cut. Hand mining of the deposit continues, gem was reported from Sri Lanka. and it is possible that more gem-quality rough During the 2016 Tucson gem shows, will be produced. Nevertheless, grandidierite Frédéric Gautier (Little Big Stone, Antananarivo, remains a very rare gem material. Madagascar) had several pieces of transparent Brendan M. Laurs FGA faceted grandidierite from new finds in the Androy region, Tuléar Province, southern Madagascar. The References initial production occurred in late 2014, when some Mitchell R.K., 1977. African grossular garnets; blue low-quality material was found. Better-quality ; cobalt spinel; and grandidierite. Journal of Gemmology, 15(7), 354–358, http://dx.doi.org/ stones were found during early- to mid-2015: 10.15506/jog.1977.15.7.354. approximately 300 kg were produced, with a very Ostwald J., 1964. Some rare blue gemstones. Journal small percentage that was transparent. Most of the of Gemmology, 9(5), 182–184, http://dx.doi.org/ gem material consisted of small pieces, with some 10.15506/jog.1964.9.5.182.

Figure 12: Weighing 1.78 ct (left) and 1.08 ct (right), these grandidierites from Madagascar are exceedingly large and transparent for this rare gem material. Photos by Jeff Scovil.

12 The Journal of Gemmology, 35(1), 2016 Gem Notes

Schmetzer K., Burford M., Kiefert L. and Bernhardt Vertriest W., Detroyat S., Sangsawong S., Raynaud V. H.-J., 2003. The first transparent faceted grandid- and Pardieu V., 2015. Gem News International: ierite, from Sri Lanka. Gems & Gemology, 39(1), 32– Grandidierite from Madagascar. Gems & Gemology, 37, http://dx.doi.org/10.5741/gems.39.1.32. 51(4), 449–450.

A Lalique Quartz , in Polarized Light

Singly polarized or cross-polarized light is often designer and well-known for his glassmaking used by gemmologists when testing transparent art, but he was also a jeweller who worked and translucent rough or cut gem materials. The with a variety of gem materials (Passos Leite, way the light is modified after passing through 2008). At first sight the pendant appeared to the material reveals important characteristics be glass, but the cool sensation of the piece about the crystalline nature of the sample. on the skin suggested it was quartz. (Glass has In October 2015, GGTL Laboratories in a lower thermal conductivity than quartz, and Geneva received for identification a colourless hence feels ‘warmer’ than quartz.) pendant (~37.1 × 34.3 × 5.1 mm; Figure 13) that Initial gemmological observations were done displayed two human figures engraved in relief. using a binocular microscope, first in transmitted The client indicated that René Lalique made light and then with crossed polarizers. Bright the pendant. Lalique (1860–1945) was a famous interference colours indicated the material was anisotropic. When we observed the pendant in the direction of the optic axis with a glass sphere Figure 13: This Lalique quartz pendant (~37.1 × 34.3 × 5.1 mm) (used as a convergent lens known as a conoscope), displays two engraved human figures. Photo by C. Caplan. we immediately saw a ‘bull’s-eye’ figure that is distinctive for quartz (Figure 14). Quartz crystallizes in the trigonal system, and the tablet used for this pendant had been cut perpendicular to the optic axis (or three- fold symmetry axis). The common habit of quartz is an elongated prism with rhombohedral terminations, and the crystals are frequently

Figure 14: Viewed with crossed polarizers, the pendant shows a ‘bull’s-eye’ interference figure with the conoscope, as expected for quartz. Distorted Dauphiné twinning interference patterns are visible in the minor rhombohedron at top and left. Photo by C. Caplan; image width ~28 mm.

Gem Notes 13 Gem Notes

Figure 15: The quartz pendant (~37.1 × 34.3 mm) shows various interference colours as the analyser is rotated over a stationary polarizer, from the front side (left) and the reverse side (right). Photos by C. Caplan. twinned (O’Donoghue, 1987). Viewed with remain colourless in the front view, while they crossed polarizers, the quartz showed angular show interference colours in the back view. The interference colour patterns on the top and left colours observed between crossed polarizers are edges of the pendant due to twinning of the complementary to those seen between parallel minor rhombohedron z faces (again, see Figure polarizers (Figure 15-right, third picture of each 14). Consistent with the fact that there was no line). This appearance is due to a combination colourless synthetic quartz available on the of diffusion and diffraction phenomena caused market during Lalique’s time, the distribution by the curved shape of the . Further, and orientation of the twinning characteristics when viewed only with fully crossed polarizers, confirmed it was natural quartz (Notari et al., completely different interference colours are 2001; Payette, 2013). produced as the pendant is rotated (Figure 16). This pendant provides a good example of It is always interesting to examine gem mater- how interference colours are influenced by the ials with polarized light, and sometimes a simple thickness of the observed material and by its colourless object can appear complexly beauti- crystallographic orientation versus the polarization ful. As shown by this pendant, such examination direction of the light. The two groups of photos yields useful information, and may allow one to in Figure 15 show variations in the appearance distinguish natural from synthetic quartz. of the pendant as the analyser was rotated over Candice Caplan ([email protected]) the stationary polarizer, from the front side (left) and Franck Notari and the reverse side (right). The human figures GGTL Laboratories, Geneva, Switzerland

Figure 16: Different interference colours are also produced as the quartz pendant is rotated between crossed polarizers. Photos by C. Caplan; image width ~20 mm.

14 The Journal of Gemmology, 35(1), 2016 Gem Notes

References Notari F., Boillat P.Y. and Grobon C., 2001. Passos Leite M.F., 2008. René Lalique at the Calouste Discrimination des améthystes et des citrines Gulbenkian Museum. Skira, Milan, Italy, 136 naturelles et synthétiques. Revue de Gemmologie, pages. 141/142, 75–80. Payette F., 2013. A simple approach to separate natural O’Donoghue M., 1987. Quartz. Butterworths, Lon- from synthetic . Australian Gemmologist, don, 110 pages. 25(4), 132–141.

Faceted Quartz with Petroleum Inclusions from Baluchistan, Pakistan Euhedral quartz crystals with petroleum inclusions heat sensitivity of the inclusions requires caution are well known from Baluchistan Province, western to avoid fracturing them. It was therefore notable Pakistan (Koivula and Tannous, 2004; Koivula, to see some of these faceted gemstones with 2008). These specimens typically have fluid Mark Kaufman (Kaufman Enterprises, San Diego, inclusions containing yellow petroleum (with or California, USA) during the 2016 Tucson gem without a colourless aqueous phase), a methane shows (e.g. Figure 17). From 30 crystals that he gas bubble and solid particles of black asphaltite. purchased at the October 2015 Munich (Germany) When exposed to UV radiation (particularly long- show, Kaufman cut six stones weighing ~1–4 wave), the petroleum commonly luminesces a ct. He selected the crystals especially to show strong yellow or blue (see, e.g., Figure 28 [right] isolated petroleum inclusions after faceting, but on p. 21). unfortunately most of the inclusions were located Koivula and Tannous (2004) indicated that too close to the surface of the crystals to avoid although gems can be cut from this quartz, the intersecting with the cutting wheel, causing the petroleum to leak out. Therefore, the greatest Figure 17: Faceted Pakistani rock crystal quartz with challenge that Kaufman faced while faceting this petroleum inclusions (yellow) is seldom encountered in the quartz was the difficulty of cutting around the marketplace. The stones shown here weigh 2.20–2.29 ct. Photo by Orasa Weldon. inclusions without penetrating them. For collectors who appreciate unusual inclu- sions, these quartz gems will provide interesting samples. Brendan M. Laurs FGA

References Koivula J.I., 2008. Lab Notes: Unusual green fluid inclusions in quartz. Gems & Gemology, 44(2), 161. Koivula J.I. and Tannous M., 2004. Gem News International: Petroleum inclusions in quartz from Pakistan: A photo-essay. Gems & Gemology, 40(1), 79–81.

Quartz Slabs from Inner Mongolia Quartz crystals are prized by collectors for their were recently described by Krzemnicki and Laurs transparency and prismatic crystal form, but some (2014) as having a radiating fibrous structure. specimens are even more interesting when sliced During the 2016 Tucson gem shows, Luciana into slabs to show their internal features. Such Barbosa (Gemological Center, Weaverville, North was the case for quartz tablets from Colombia that Carolina, USA) had some interesting quartz

Gem Notes 15 Gem Notes

Figure 18: These polished slices of quartz from Inner Mongolia (up to 2.8 cm tall) display various six-fold patterns. Courtesy of Mike and Pat Gray; photo by Jeff Scovil.

slabs from the Huanggang Fe-Sn deposit, Inner process of being slabbed. The slices typically Mongolia, China. Polished perpendicular to ranged up to 3 cm across, with very few being the c-axis, some of them displayed snowflake- any larger. Only some portions of the crystals like patterns of dark inclusions, while others gave attractive patterns when sliced. The dark had transparent cores that showed complex inclusions have not yet been identified. patterns of interference colours between crossed Brendan M. Laurs FGA polarizers (Figures 18 and 19). Reference Barbosa was told that the quartz was found Krzemnicki M.S. and Laurs B.M., 2014. Gem Notes: in 2012. She obtained ~100 slices for the Tucson Quartz with radiating fibres, sold as ‘trapiche’ shows, with an additional ~50 pieces in the quartz. Journal of Gemmology, 34(4), 296–298.

Figure 19: Close-up images of the quartz slabs from Inner Mongolia reveal attractive radiating and concentric arrays of dark inclusions (left, 30 × 27 × 2 mm) and complex patterns of interference colours (right, 26 × 25 × 2 mm). Photos by Luciana Barbosa; crossed polarizers.

Sphalerite Inclusions in Quartz

During the 2016 Tucson gem shows, rare-stone reported that about 80 stones were faceted from dealer Luciana Barbosa had some faceted quartz a single large quartz crystal that was mined in with sphalerite inclusions from a new find in 2015, which contained numerous sphalerite Goiás State, (e.g. Figure 20). Barbosa crystals near the surface. The largest gem

16 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 20: This 34.20 ct quartz from a new find in Brazil contains two euhedral inclusions of sphalerite. Courtesy of Luciana Barbosa; photo by Jeff Scovil. weighed over 100 ct, but most of the stones were <20 ct. Although sphalerite inclusions have been reported previously in quartz (i.e. from Figure 21: A closer view of the larger sphalerite inclusion (4 deposits and various ore veins; Hyršl, 2006), this mm across) in Figure 20 shows interesting growth patterns on some of its faces. Photo by Jeff Scovil. find is notable for the clarity of the host quartz and the perfection of the sphalerite crystals, some Reference of which even display complex growth patterns Hyršl J., 2006. Genetic classification of mineral on their faces (Figure 21). inclusions in quartz. Gems & Gemology, 42(3), Brendan M. Laurs FGA 97–98.

Ruby from Liberia

Ruby from Liberia was reported relatively Figure 22: This polished hexagonal plate (3.32 ct) of recently by Kiefert and Douman (2011) as small ruby from Liberia displays abundant sparkles in reflected transparent pinkish red to red pebbles from the light that are due to reflections from rutile inclusions and polycrystalline grain boundaries. Photo by B. Williams. Mano River, and larger near-opaque purplish red crystals from Nimba Province near the Guinean border. During the 2015 and 2016 AGTA Tucson gem shows, Eric Braunwart (Columbia Gem House, Vancouver, Washington, USA) displayed ruby from Liberia that was different from either material mentioned above. While not of facet grade, it exhibited an attractive sparkliness in reflected light. Braunwart loaned the sample in Figure 22 for examination. It consisted of a polished hexagonal plate weighing 3.32 ct and measuring 10.16 × 1.96 mm. It was a dull but saturated dark red (World of Color 2.5R3/6, Dark Red) with slight to moderate

Gem Notes 17 Gem Notes

Figure 23: Seen here in oblique lighting, the 3.32 ct Figure 24: Viewing the 3.32 ct ruby with transmitted light ruby shows a granular texture with orangey red domains highlights the presence of a partially healed fissure and corresponding to rutile inclusions. Photo by B. Williams. abundant orangey red inclusions (rutile crystals). Photo by B. Williams. translucency. Although the hexagonal slice had It is the sparkly appearance that makes this a shape reminiscent of a cross-section from a ruby intriguing. Under magnification, numerous corundum crystal, the stone gave a polycrystalline micro-reflections were seen emanating from the reaction between crossed polarizers, remaining polycrystalline grain boundaries, as well as from bright throughout a full rotation. Microscopic the inclusions mentioned above. Several of the observation revealed a granular appearance surface-reaching inclusions were identified as with most individual grains appearing pinkish rutile by an Enwave 785 micro-Raman spectro- red, while a few were orangey red (Figure 23). meter. The presence of abundant rutile inclusions While this might be suggestive of ruby dichroism, is consistent with the elevated Ti content ob- the orangey red domains proved to consist of tained for the sample with an Amptek X123- inclusions. Transmitted light revealed numerous SDD EDXRF spectrometer. The chemical analysis translucent, deep orangey red, blocky, crystalline also revealed the Cr and Fe that are presumed inclusions that were randomly oriented, as well responsible for the red colour of the ruby and as one partially healed fissure running through lack of fluorescence, respectively. the centre of the stone (Figure 24). No other While ruby with rutile needles is commonly inclusions were observed. RI measurements encountered, this material in unusual for having of the sample yielded a single, weak shadow rutile present as reflective grains mixed with edge near 1.763. Specific gravity was measured polycrystalline ruby. as 3.81; this relatively low value is possibly due Cara Williams FGA and Bear Williams FGA to the corundum’s polycrystalline structure. The Reference stone was inert to both long- and short-wave UV Kiefert L. and Douman M., 2011. Gem News Inter- excitation. Raman analysis with a GemmoRaman- national: Ruby from Liberia. Gems & Gemology, SG instrument confirmed it to be corundum. 47(2), 128.

Yellow Sapphire with Unstable Colour—in Reverse Irradiated yellow sapphires are rarely encountered to colourless upon exposure to light (Nassau in today’s market. Although it is possible to and Valente, 1987). We were therefore surprised irradiate a colourless sapphire to turn it yellow, to learn about a yellow sapphire with unstable this treatment is highly unstable and readily fades colour—in reverse. Harold Dupuy FGA of Stuller

18 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 25: This 1.07 ct sapphire shows an unusual ‘reverse’ colour change. The more stable yellow state fades to colourless after low-temperature heating, and the yellow colour can be restored by exposure to long-wave UV radiation or daylight. Photos by B. Williams.

Inc., Lafayette, Louisiana, USA, reported that it to be observed only in approximately 1 in 3,000 they sold a 1.07 ct white sapphire to a retailer yellow sapphires. In such cases, the yellow colour who returned the stone after it turned yellow. is more stable, and fades to colourless when The client mounted the white sapphire into a exposed to heat (such as during the jewellery- ring, and sold it to a consumer who wore the making process), but reverts to the original ring for a few months before returning it to the yellow upon exposure to sunlight for a few days. retailer. Stuller immediately exchanged the stone In the present sapphire, -visible-near for another comparable white sapphire, but the infrared (UV-Vis-NIR) spectroscopy showed a question remained of how and why the change small absorption at 450 nm in both colour states in coloration occurred. that is indicative of iron (not responsible for the The sapphire was sent to Stone Group colour phenomenon). The spectra also revealed a Laboratories for testing. Upon receipt, the stone very subtle difference between colour states in the was yellow (Figure 25, left). The refractometer form of a broad absorption band in the 460–480 showed the expected RI values of 1.76–1.77 and nm range for the yellow state, which was most Raman spectroscopy confirmed it was corundum. likely related to the observed change in coloration. Detailed microscopic examination and FTIR All of the conditions that were found capable of spectroscopy revealed the absence of thermal altering the colour of this sapphire are commonly enhancement in this metamorphic sapphire. With experienced by gem materials in general. Dupuy’s permission, various experiments were Long-wave UV radiation is encountered in the performed to test the colour stability of the stone. laboratory environment as well as in tanning beds. First the sapphire was subjected to low- Of course, sunlight is an even more common temperature heating of 260°C for one hour, which source of long-wave UV wavelengths. Heating rendered it colourless (e.g. Figure 25, right). Then to a temperature of 260°C is comparatively mild, it was exposed to a 4 W long-wave UV lamp for such that it may be produced by typical kitchen 30 minutes, after which it again appeared light ovens, and jewellery processes can often expose yellow. Reheating as before returned it to colour- gems to much higher temperatures. Heating of less. Such reversible coloration is commonly this sapphire to 260°C did not induce a 3309 related to energy-induced trapped hole centres, cm−1 band in the FTIR spectra, such as seen in which can vary in their stability (Nassau and heated corundum. More research is required to Valente, 1987). A reversible colour change also understand the coloration of this sapphire, which has been observed by the present authors in is best described as containing a rare but unstable some blue that exhibit brown-to-green energy-activated colour centre. tints upon exposure to strong UV radiation, then Cara Williams FGA and Bear Williams FGA revert to their previous (heated) blue colour over a period of days when exposed to a broad- References spectrum visible light (cf. Renfro, 2013), or more Nassau K. and Valente G.K., 1987. The seven types quickly revert to blue with slight heating. of yellow sapphire and their stability to light. Gems & Gemology, 23(4), 222–231, http://dx.doi. Jay Boyle (Jay Boyle Co., Fairfield, Iowa, org/10.5741/gems.23.4.222. USA), who has been dealing in untreated yellow Renfro N.D., 2013. Reversible color modification of and white sapphires for 35 years, says he has blue by long wave ultraviolet radiation. encountered a small number of yellow stones Geological Society of America Abstracts with that exhibited this colour behaviour. He believes Programs, 45(7), 835.

Gem Notes 19 Gem Notes

Petroleum Inclusion in Pink Spinel Recently, American Gemological Laboratories had the opportunity to examine an unusual 1.69 ct pink spinel that reportedly came from Sri Lanka (Figure 26). Microscopic examination revealed some inclusions commonly seen in spinel, consisting of variously sized octahedral crystals, planar internal growth structures and open fissures. However, most conspicuous was a sizeable two-phase inclusion positioned under the table and in the heart of the stone. The euhedral negative crystal contained a viscous yellow fluid and a spherical bubble (Figure 27, left). As the Figure 26: This 1.69 ct pink spinel, reportedly of Sri Lankan stone was turned, the bubble slowly moved origin, contains a unique petroleum-bearing inclusion under through the thick yellow fluid. When viewed in the table facet. Photo by Bilal Mahmood. a darkened room with long-wave UV radiation (365 nm), the fluid in this inclusion displayed a this spinel has a similar viscous yellow character chalky blue-white reaction underlying the distinct (see Figure 27, right) and displays the same chalky reddish glow of the host spinel (Figure 28, left). blue-white long-wave UV reaction (see Figure 28, Raman analysis could not be used to analyse right) as the petroleum in quartz from Pakistan. the fluid due to strong luminescence To the authors’ knowledge, this is the first that swamped the detector. However, focused time that a petroleum-bearing inclusion has been infrared spectroscopy using a paper mask around documented in spinel. the inclusion (Figure 29) identified the fluid as Monruedee Chaipaksa ([email protected]) petroleum. The spherical bubble was presumably and Christopher P. Smith a gas, although it could have been an immiscible American Gemological Laboratories fluid, such as water. New York, New York, USA Similar negative crystals are well-known in Reference rock crystal quartz from Baluchistan, Pakistan (see Koivula J.I., 2008. Lab Notes: Unusual green fluid e.g. Koivula, 2008), which contain petroleum and inclusions in quartz. Gems & Gemology, 44(2), a bubble of methane gas. The petroleum fluid in 161.

Figure 27: Left: The large, two-phase negative crystal in the spinel contains a viscous yellow fluid (petroleum) and a spherical bubble consisting of a gas or immiscible fluid. The bubble could be seen to slowly migrate through the petroleum as the stone was turned. Photomicrograph by M. Chaipaksa; magnified 70×. Right: A similar appearance is displayed by petroleum-filled negative crystals in colourless quartz crystals from Baluchistan, Pakistan. Photomicrograph by C. P. Smith; magnified 24×.

20 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 28: Left: Under long-wave UV radiation (365 nm), the petroleum exhibits a chalky blue-white reaction that was somewhat muted by the dominant red luminescence of the host spinel. Right: Such fluorescence also is displayed by petroleum inclusions in a Pakistani quartz. Photomicrographs by C. P. Smith; magnified 40×.

Figure 29: Focused infrared spectro- IR Spectrum scopy of the negative crystal in the 2925 spinel identified the viscous yellow

2955 fluid as petroleum, with lines at 2955, −1 2855 2925 and 2855 cm . The inclusion was isolated for the analysis by using a 1.5-mm-wide paper mask (inset photomicrograph by C. P. Smith).

3200 2700 Absorbance Absorbance

5500 5000 4500 4000 3500 3000 2500 2000 1500 Wavenumber (cm−1)

Spurrite from New Mexico, USA

Spurrite is a calc- with the formula faceted spurrite from Tres Hermanas Mountains,

Ca5(SiO4)2(CO3) and a Mohs hardness of 5. It Luna County, New Mexico, USA (cf. Homme typically forms in contact metamorphic rocks and Rosenzweig, 1970). He had 15 pieces that (in particular, skarn deposits) as granular masses averaged 3 ct each (e.g. Figure 30). Pantò kindly ranging from colourless to greyish violet (Bernard donated one of the spurrites to Gem-A, and the and Hyršl, 2004). The mineral has only rarely gem was characterized by authors CW and BW. been used for purposes (e.g. purple The following properties were recorded from beads and polished slabs or freeform pieces from the 1.86 ct stone: colour—greyish lilac purple; dia- Mexico and south-western USA; Koivula and phaneity—translucent; RI—approximately 1.67 Misiorowski, 1986; Wentzell, 2004). (indistinct, using the bright line technique); During the 2015 Tucson gem shows, Mauro Pantò hydrostatic SG—3.00; fluorescence—inert to (The Beauty in the Rocks, Laigueglia, Italy) had long- and short-wave UV radiation; polariscope—

Gem Notes 21 Gem Notes

aggregate reaction; Chelsea filter—light pinkish red; and no absorption features were visible with a desk-model spectroscope. These properties are consistent with those reported for spurrite in the literature, except that Wentzell (2004) documented faint ‘cobalt’-blue long-wave UV luminescence in samples from Mexico. Microscopic examination revealed little other than minor surface-reaching fissures, grain boundaries typical of a polycrystalline material and a few tiny dark masses. Figure 30: These translucent purple gemstones (3.14– Raman analysis using an Enwave L-Series 5.73 ct) are spurrite from New Mexico, USA. Photo by Mauro spectrometer with a 785 nm laser gave a very Pantò. good match to spurrite in the RRUFF database and in our own reference spectra. EDXRF sample from New Mexico, as indicated by the chemical analyses using an Amptek X123-SDD anomalous trace elements and the tiny black instrument with a DP5 preamplifier showed that masses. Fe was the main impurity, along with minor-to- Spurrite is dimorphous with paraspurrite, trace amounts of Mn, Cr, Zn and Pb. The presence which has mostly overlapping gemmological of small amounts of mineral impurities (such properties but is known only from Inyo County, as carbonates) was documented by Wentzell California, USA (Bernard and Hyršl, 2004). (2004) in spurrite from Mexico. Minute amounts Cara Williams FGA, Bear Williams FGA of mineral impurities also were present in our and Brendan M. Laurs FGA

References Bernard J.H. and Hyršl J., 2004. Minerals and Their Mountains–Florida Mountains Region, 141– Localities. Granit, Prague, Czech Republic. 145. Homme F.C. and Rosenzweig A., 1970. Contact Koivula J.I. and Misiorowski E., 1986. Gem News: metamorphism in the Tres Hermanas Mountains, Tucson 1986. Gems & Gemology, 22(2), 114– Luna County, New Mexico. In L.A. Woodward, 115. Ed., New Mexico Geological Society Fall Field Wentzell C.Y., 2004. Lab Notes: Spurrite. Gems & Conference Guidebook – 21: Tyrone–Big Hatchet Gemology, 40(1), 63–65.

Update on Tsavorite Mining at the Scorpion Mine, Kenya The history and mining of tsavorite at Kenya’s and a new road to the Green Garnet 3 (GG3) Scorpion mine and surrounding claims was operation was constructed after the old road described by Bridges and Walker (2014), and was destroyed by past rainy seasons. The GG2 since then many important developments site has been renovated to repair most of the have occurred. After a six-year hiatus, the damage done by many years of illegal mining. operations were reopened in January 2015. The former ‘CW’ open pit (where very fine- This was accomplished after major investments colour tsavorite and some tourmaline were in infrastructure and staffing, improved mining previously mined) has been reclaimed. Both processes and newly implemented safety the main camp and supervisor camp were measures—all in an effort to ramp-up tsavorite restored after elephant attacks caused severe production. damage. The staff quarters also were upgraded Among the infrastructural improvements, to accommodate a labour force that expands to access roads to the Scorpion mine and outlying approximately 100 people during the height of claim areas were upgraded for better access, the mining season. The main camp has been

22 The Journal of Gemmology, 35(1), 2016 Gem Notes

Figure 31: Miners sort through waste rock at the working face of Scorpion mine tunnel No. 4. The ceiling in this area has been reinforced with split-sets. Photo by Louis Brunet.

entirely equipped with solar power, and a new Production of tsavorite from the Scorpion mine workshop has been constructed. (and later from GG2) resumed in mid-July 2015, and To improve mining efficiency, an 85 kVA several small-to-medium-sized nodules have been generator was installed at the Scorpion mine to encountered so far. Most of the gem rough (e.g. power larger fans and two mono-winches that can Figure 32) consisted of pieces weighing 0.1–0.5 g, be used to remove approximately 4–5 tonnes of with a small percentage in the 1–20 g range. The waste rock per hour. To enable the use of two rock colour ranged from a vivid light yellowish green to drills simultaneously, a high-pressure compressed a vibrant deep bluish green, with some attractive air pipe has been installed into both the No. 2 medium green stones produced (e.g. Figure 33). and No. 4 inclines. The existing ventilation system Tsavorite in larger calibrated sizes such as 7 × 5 was also upgraded to improve air circulation. mm, 8 × 6 mm, 9 × 7 mm, etc. has always been Two new airlift pumps were purchased that run extremely hard to come by. However, the recent on compressed air instead of petrol/diesel, for production has enabled the creation of complete a safer and cleaner work environment. Six new tsavorite suites (e.g. Figure 34). For the first time rock-drilling machines were obtained that are in many years, multiple suites of graduated and specially designed for operating with water and calibrated tsavorite rounds have been cut, ranging compressed air. These make drilling much easier from 2.0 to 8.5 mm. The largest faceted stone from and also minimize the drillers’ exposure to silica recent production weighed 17.20 ct. dust. A 40,000 litre water tank has been installed To help ensure future production of tsavorite, at the Scorpion mine to ensure a continuous water several knowledgeable geologists were brought supply, and a water bowser (tanker rig) was built on to assess the mining areas and assist with for transporting water to other locations such as mapping the local geology and reef zones at GG3. To improve underground safety, split-sets Scorpion and GG2. In addition, around Snake (roof bolts) have replaced the timber and steel Hill and at other tsavorite-bearing locations, girder supports previously utilized in the No. 2 approximately 350 cubic metres of earth were and No. 4 tunnels (e.g. Figure 31). Problematic removed for bulk sampling. areas of the tunnels have been reinforced with Unfortunately, activities by illegal miners and welded mesh to help retain friable hanging-wall bandits remain a problem in the lease areas, and material. some encroachers have been arrested by the

Gem Notes 23 Gem Notes

Figure 32: Recently produced tsavorite rough from the Figure 33: This large (~7 g) piece of tsavorite displays an Scorpion mine is in the process of being sorted. Photo by excellent medium green colour and a good shape for cutting. B. Bridges. Photo by B. Bridges.

Kenya Police. There is a strong push by a large operation. The family is hopeful that they Kenyan organized crime syndicate to take over will be able to continue with minimal outside the tsavorite mining region in southern Kenya. interference and be allowed to further develop Our activities continue to be impacted by threats their tsavorite reserves. of violence similar to that which led to the Bruce Bridges ([email protected]) murder of the mine’s original owner, Campbell Bridges Tsavorite, Tucson, Arizona, USA Bridges, in 2009. With the mine finally in production once Reference more, this represents a new chapter for Bridges B. and Walker J., 2014. The discoverer of tsavorite in Kenya, which has contributed to tsavorite—Campbell Bridges—and his Scorpion the excitement and optimism the gem industry mine. Journal of Gemmology, 34(3), 230–241, shares for the future of the Bridges’ mining http://dx.doi.org/10.15506/jog.2014.34.3.230.

Figure 34: The graduated and calibrated round brilliants in this tsavorite suite range from 3.5 to 8.5 mm for the neck- lace stones, and the matched pair has a total weight of 10.76 ct. Photo by Jeff Scovil for Bridges Tsavorite.

24 The Journal of Gemmology, 35(1), 2016 Gem Notes

PEARLS

Natural Mussel Pearls from the Philippines

In the Philippines, the brown mussel (Modiolus 3. Mauve (mostly baroque) philippinarum) is harvested for food on a • Two lines: each ~18″ (45.7 cm) long, 1.5– subsistence basis, and also has been used as 6.0 mm diameter, 90.67 ct total weight an inexpensive source of aquaculture feed • One graduated line: 4.61″ (11.7 cm) long, (e.g. Napata and Andalecio, 2011). Natural 2.0–5.3 mm diameter, 10.62 ct total weight mussel pearls from Modiolus philippinarum • Two tassels: each 2.5″ (6.4 cm) long, 1.5– are virtually unknown in the gem trade, and 3.0 mm diameter, 73.72 ct total weight it was therefore surprising to see hundreds of The ‘black’ pearls were mostly medium-to- them during the 2016 Tucson gem shows with dark purple with some light-coloured pieces one pearl dealer, K.C. Bell (KCB Natural Pearls, (particularly among the rounds) in various purple, San Francisco, California, USA). Bell reported blue and golden shades. Overtones of pink and collecting the pearls from his Philippine lavender were visible in some of the rounds. The supplier for at least 10 years. All of them were mauve pearls consisted of light-to-medium shades drilled and strung, and he divided them into of cream, brown and grey, with overtones. three general varieties (e.g. Figure 35) consisting Various surface features included dimples and of the following pieces: wrinkles; only a few circled pearls were present. 1. Black round Although Modiolus philippinarum pearls are • Three lines: each ~17.5 (44.5 cm) long, ″ rarely encountered, this collection shows how 1.0–5.3 mm diameter, 65.86 ct total weight large numbers can be amassed over a long time. • Two tassels: each 2″ (5.1 cm) long, 3.0– Brendan M. Laurs FGA 6.5 mm diameter, 54.75 ct total weight 2. Black baroque Reference • Two lines: each ~16″ (40.6 cm) long, 2.0– Napata R.P. and Andalecio M.N., 2011. Exploitation and management of brown mussel (Modiolus 9.4 mm diameter, 150.76 ct total weight philippinarum) resources in Iloilo, Philippines. • Two tassels: each 2.5″ (6.4 cm) long, 2.0– Philippine Journal of Social Sciences and 9.5 mm diameter, 74.00 ct total weight Humanities, 16(2), 22–34.

Figure 35: These are some of the natural pearls (up to 9 mm) collected in the Philippines from the brown mussel Modiolus philippinarum. From left to right, pearl varieties have been classified into mauve, black round and black baroque. Photo by Jeff Scovil.

Gem Notes 25

t Circ Firs ular & C a l l

f Save your dates o

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2016 “The Fullmoon of r 14 -15 November GemUnity” The 5th GIT International Gem and Jewelry Conference with Pre - and Post - Conference Excursions PATTAYA, THAILAND

The Fullmoon of GEMUnity November 14–15, 2016, Pattaya, Thailand

Conference Dates: Registration Fees: November 14-15, 2016: Technical session, oral • Early bird USD 200, after Sep 30 USD 300 & poster presentations • Student USD 100, after Sep 30 USD 150 November 9-13, 2016: Pre-conference excursion to • On-Site USD 350 the legendary gem deposits, Myanmar • *Pre-conference excursion to Mogok USD 1,800 or less November 16-18, 2016: Post-conference excursion to (Air ticket to Mandalay and Visa for Myanmar excluded) Chanthaburi, the world’s capital of colored stones & • *Post-conference excursion to Chanthaburi & Trat, Trat, home of the renowned Siamese Ruby Thailand USD 300 (*Limited seats available for excursion only on Venue: the rst come rst serve basis) Pattaya, the world’s premiere beach resort, Thailand Special rates oered for accommodations Highlights: Further information announced on the GIT website • Keynote addresses by top-notched speakers • Creative forums by top designers, gemologists Important Dates and business leaders • Topics submission by May, 2016 • CSR from the mine to the market • Extended abstract submission by August, 2016 • Global gem and jewelry networking • Adventurous excursions to gem fields Themes: and historical sites • Gem & deposits, exploration • Intimate gem community rendezvous and responsible mining • Bangkok rendezvous of the World’s Ruby Secretariat Office: • Innovation identification & characterization Tel: +66 2634 4999 ext. 453 • Treatment & synthetics update and disclosure Email: [email protected] • Gem quality standards & gem optics Website: www.git.or.th and color science • Jewelry trend & design • Manufacturing & cutting edge technology • Ethical, policy & good governance issues • World gem & jewelry trading and ASEAN market Feature Article

Characterization of Oriented Inclusions in Cat’s-eye, Star and Other Chrysoberyls

Karl Schmetzer, Heinz-Jürgen Bernhardt and H. Albert Gilg

Milky-appearing alexandrite samples from Tanzania (Lake Manyara) and India (Kerala) were examined, as were chatoyant and asteriated / alexandrite from India (Orissa), Brazil, Madagascar and Sri Lanka, and also phenomenal synthetic alexandrite from Kyocera in Japan. Sixteen oriented thin sections were studied by a combination of optical microscopy, micro-Raman spectroscopy, and electron microprobe techniques employing backscattered electron (BSE) imaging, qualitative point analysis and Ti compositional mapping. Rutile was identified as needle-like inclusions and V-shaped platelets in planes perpendicular to the a-axis, elongated parallel to the c-axis, and parallel to symmetry-equivalent <011> directions. Additional structures consisting of rutile needles and/or channels in various samples were oriented parallel to the a-axis. Also observed were single or multiple-intergrown rutile platelets elongated parallel to the a-axis, and rutile platelets showing rectangular, L-shaped or zigzag cross- sections parallel to <012> directions. In a four-rayed star chrysoberyl, elongated particles were oriented along the c-axis. Various optical effects such as a whitish appearance, or are caused by, and depend upon, the presence, size and concentration of the combined different types of needle- like or platy inclusions.

The Journal of Gemmology, 35(1), 2016, pp. 28–54, http://dx.doi.org/10.15506/JoG.2016.35.1.28 © 2016 The Gemmological Association of Great Britain

Background By analogy, numerous studies have dealt with The examination of needle-like mineral inclusions the examination and identification of the needle- and elongated cavities or channels in gem materials like precipitates in corundum (specifically Ti-doped has always been of interest to gemmologists synthetic and Fe- and Ti-bearing natural material). because these features are responsible for The different phases present as acicular inclusions chatoyancy and asterism in cabochon-cut samples. have been characterized via transmission electron Identifying such inclusions, however, has often microscopy using electron diffraction and/or other proved problematic since their dimensions are micro-analytical techniques. The inclusions often frequently below the resolution of gemmological have been described as twinned rutile needles, microscopes (magnification up to 100×). although the presence of rhombic or monoclinic

28 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure 1: This pendant features a cat’s-eye alexandrite, presumably from Sri Lanka, and is shown in daylight (left) and incandescent light (right). The stone measures 13.62 × 13.72 × 9.05 mm and weighs 14.52 ct. Courtesy of David Humphrey, Pacific Palisades, California, USA; photo by Erica and Harold Van Pelt.

TiO2 phases and even the formation of Al2TiO5 or channel structures were found to be parallel have been reported as well (Phillips et al., 1980; to the crystallographic a-axis [100], with the Langensiepen et al., 1983; and Phillips, single light band of the cat’s-eye being observed 1991; Xiao et al., 1997; Viti and Ferrari, 2006; He perpendicular to the needle axis (Schmetzer and et al., 2011). Hainschwang, 2012). Oriented structures in chrysoberyl, in contrast, With respect to asteriated material, six-rayed have received less attention. It is evident from natural chrysoberyl is almost unknown and only the observed that oriented has been mentioned occasionally (Kumaratilake, inclusions are present in both cat’s-eye (e.g. 1997; McClure and Koivula, 2001), while four- Figure 1) and star chrysoberyl. The chatoyancy rayed chrysoberyl is extremely rare, originating has been ascribed to hollow channels or needle- mostly from Sri Lanka (Schmetzer, 2010). In the like mineral inclusions such as rutile (Eppler, latter material, the two intersecting light bands 1958), a view broadly repeated in standard normally show different intensities, and the gemmological texts. Through examinations needle-like inclusions or channels that cause these involving a large number of samples from sources bands have not been identified unequivocally. worldwide, a consistent orientation for these In a study of cat’s-eye and non-phenomenal inclusions has been established. The needle-like chrysoberyls from Brazil, precipitates (exsolu-

Oriented Inclusions in Chrysoberyl 29 Feature Article

a b

Figure 2: This alexandrite from Lake Manyara, Tanzania, shows relatively large needle-like inclusions (rutile needles and/or channels) parallel to the a-axis. (a) In a view exactly parallel to the a-axis, the inclusions appear as small rounded dots forming sequences of parallel lines (indicated by arrows), and growth planes parallel to the i prism faces appear sharp. (b) In a view inclined to the a-axis, the elongate nature of the inclusions is visible. Immersion, field of view 2.7 × 2.0 mm; photomicrographs by K. Schmetzer. tions) of rutile were identified by electron perpendicular to the a-axis; within these planes, the diffraction and micro-analytical techniques in inclusions are oriented parallel to the c-axis [001] one chatoyant sample (Marder and Mitchell, and to the i and –i {011} prism faces (Schmetzer 1982). The rutile inclusions were described as et al., 2013), equivalent to orientations parallel to “elongated plates about 0.1 µm thick”, but their the [001] and <011> directions (see again Box A; orientation was not mentioned. Nonetheless, an for simplicity, this latter nomenclature convention analogy between chrysoberyl and corundum was will generally be used herein). Accordingly, the proposed, with the three directions in chrysoberyl three different series of needles form angles of parallel to the c-axis [001] and parallel to <011> ~60° with each other. directions being equivalent to the three directions observed for rutile needles in corundum. (For an explanation of the nomenclature referring to Authors’ Previous Work and the crystallographic directions and their respective Aim of This Study axes in chrysoberyl as employed in this article, In alexandrite from the Lake Manyara deposit in see Box A.) More recently, two series of oriented Tanzania, various types of oriented inclusions inclusions described as rutile precipitates along are observed, mainly in milky-appearing crystals k and –k {021} faces were studied by electron exhibiting pervasive cloudy whiteness throughout diffraction in a chrysoberyl from Brazil (Drev the entire piece, or in samples with alternating et al., 2015). The equivalent directions of those milky areas and transparent green growth zones. elongated structures would be <012>, and the An initial study revealed that the inclusions are maximum length of the precipitates was 0.05 µm. developed as needles or channels elongated The relationship between the crystal structures parallel to the a-axis [100] and as small particles of the chrysoberyl host and those of the rutile concentrated in planes perpendicular to the exsolutions was discussed in detail by Drev et al. a-axis (Schmetzer and Malsy, 2011; see Figures (2015), but the dimensions of the precipitates in 2 and 3). A polished thin section oriented almost the direction parallel to the a-axis [100] has not perpendicular to the a-axis showed at high yet been determined (Prof. A. Recˇ nik [Jožef Stefan magnification three series of flattened needles or Institute, Ljubljana, Slovenia], pers. comm., 2016). platelets oriented with their flat faces parallel to Synthetic alexandrite grown by Kyocera of that plane. Japan shows three series of needle-like inclusions In a subsequent study of a completely (most likely rutile exsolutions) lying in planes milky, translucent alexandrite crystal from Lake

30 The Journal of Gemmology, 35(1), 2016 Feature Article

but like the earlier work, this study did not report a-axis the compositional nature of the inclusions. The current examination was undertaken a to further investigate the presence and nature plane of oriented inclusions in milky-appearing alexandrite from Lake Manyara. Moreover, this study offered an opportunity for wider applic- ability in understanding similar natural and synthetic materials. For instance, the inclusion pattern described above and pictured in Figure 3 is seen not only in material from Lake Manyara, but also in alexandrite from other localities (e.g. India). Therefore, this study was expanded in an effort to elucidate whether alexandrite/ chrysoberyl from other locations might likewise show a pattern of oriented inclusions analogous to that observed in the Lake Manyara material. An Figure 3: Alexandrite (shown here) and chrysoberyl from example is presented here for semi-transparent Lake Manyara frequently contain areas with needles samples from the state of Kerala in India. or channels oriented parallel to the a-axis, as well as Yet another opportunity to augment this minute inclusions in layers parallel to the a plane. View inclusion study was afforded by chatoyant and perpendicular to the a-axis, immersion, polarized light, field of view 4.5 × 4.5 mm; photomicrograph by K. Schmetzer. asteriated material. As noted above, the elongated inclusions responsible for the chatoyancy in chrysoberyl from various sources were found Manyara, polished thin sections were prepared to be parallel to the a-axis [100] (Schmetzer in orientations perpendicular to the a-axis and and Hainschwang, 2012). Additionally, from the almost perpendicular to the c-axis (Schmetzer orientation of the two intersecting light bands in and Bernhardt, 2012; Figures 4 and 5). The natural four-rayed star chrysoberyl, presumably inclusion pattern observed in the section cut from Sri Lanka, it had been concluded that perpendicular to the a-axis (Figure 4) was similar to that described by Schmetzer and Malsy (2011), Figure 5: In this view of a thin section cut approximately perpendicular to the c-axis, a Lake Manyara alexandrite Figure 4: In a thin section cut perpendicular to the a-axis, has needle-like inclusions parallel to the a-axis. In some this alexandrite from Lake Manyara displays needle-like areas, other inclusions are concentrated on a (100) inclusions oriented in three directions. Intergrowths between planes (perpendicular to the a-axis), and cross-sections two needles commonly form V-shaped angular structures or of these inclusions are seen in this orientation of the thin even triangular platelets. Transmitted light, field of view 120 section. Transmitted light, field of view 140 × 105 µm; x 90 µm; photomicrograph by H.-J. Bernhardt. photomicrograph by H.-J. Bernhardt.

a-axis

a plane

Oriented Inclusions in Chrysoberyl 31 Feature Article

Box A: Nomenclature for Crystal Faces and Crystallographic Directions in Chrysoberyl

To facilitate understanding of the orientation dimensions of a = 4.42 Å, b = 9.39 Å and c = of elongated inclusions (needle-like, channel 5.47 Å were used for the three crystallographic or platelet structures) in chrysoberyl varieties, axes. and especially to avoid excessive repetition in All symmetry-equivalent faces of a crystal the text, this box gives a few general points are referred to as a crystal form, and the faces of about designating faces and directions in the such a crystal form are symbolized using braces. orthorhombic . For example, chrysoberyl has four symmetry- – The three crystallographic axes of chrysoberyl equivalent i (011) prism faces, i.e. (011), (011), – –– are normally indicated using the simple letters (011) and (011), which are identified by the a, b and c. The three crystal faces perpendicular symbol {011} for the crystal form equivalent to to these axes are correspondingly designated as all four such crystal faces (Figure A-1). a, b and c. A more detailed system of notation Crystallographic directions other than the employing what are referred to as Miller three crystal axes are also designated with indices in parentheses (hkl) specifies the faces the symbol [uvw]. They commonly represent perpendicular to the three axes as (100) for a, edges between two crystal faces. There are, (010) for b and (001) for c. A similar notation for instance, four symmetry-equivalent edges involving three numbers in brackets [uvw] can between the four i {011} prism faces and the – be applied to the axes: [100] for the a-axis, [010] a (100) pinacoid. These four edges [011], [011 – –– for the b-axis and [001] for the c-axis (Table ], [011] and [011] are indicated jointly by the A-1). For purposes of the present paper, cell symbol <011>.

Table A-1: Oriented inclusions in chrysoberyl varieties; nomenclature of crystal faces and crystallographic directions. Crystal Axes and Faces

Face perpendicular to Crystal axis Symbol [uvw] Cell dimensions (Å) Miller index (hkl) the crystal axis

a-axis [100] 4.42 Pinacoid a (100) b-axis [010] 9.39 Pinacoid b (010) c-axis [001] 5.47 Pinacoid c (001)

Needle-like Inclusions or Channels Parallel to Crystal Axes Orientation Symbol Observed in chrysoberyl ║a-axis [100] Yes ║b-axis [010] No ║c-axis [001] Yes

Needle-like Inclusions or Rectangular Cross-Sections Parallel to the Edges Formed by Two Intersecting Crystal Faces Miller index Direction of crystal Angles between symmetry- First face Miller index (hkl) Second face {hkl} edges equivalent crystal edges Pinacoid a (100) Prism i {011} <011> 60.44° and 119.56° Pinacoid a (100) Prism k {021} <012> 81.28° and 98.72°

32 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure A-1: This diagram shows the morphology of A B chrysoberyl and alexandrite crystals and the orientations c c i i i of their acicular inclusions or platelets. Drawing A is an k k k idealized clinographic projection of a crystal formed by the pinacoids a {100}, b {010} and c {001} in combination with the prisms i {011} and k {021}. Drawing B is a view b c c of the same crystal parallel to the a-axis, representing the orientation of thin sections cut perpendicular to the b a-axis. Part C displays the orientation of different series b a b of needle-like inclusions in such thin sections, showing needles oriented parallel to the c-axis [001] and to the b a <011> directions (left), and cross-sections of flattened a k k needles or elongated platelets parallel to the <012> i i directions (right). Part D depicts the possible orientations c of intergrown structures or twins parallel to the <011> and <012> directions, giving the angles formed by the C needles parallel to <011> and by the inclusion cross- sections parallel to <012>. All drawings by K. Schmetzer.

<011> <012>

[001]

D 119.56° 81.28°

60.44° 98.72°

<011> <012>

Crystal edges between two faces with the k {021} prism faces, symbolized by <012>.

Miller indices (h1k1l1) and (h2k2l2) are easily All needles or channels parallel to the directions calculated with the formula: [001] or <011>, and the inclusion cross-sections

u = k1•l2 – l1•k2 parallel to <012>, are located within the a (100)

v = l1•h2 – h1•l2 plane or are observed in sections parallel to the

w = h1•k2 – k1•h2 a (100) plane. The various forms of needles, In chrysoberyl, several series of needle-like platelets or channels with cross-sections seen inclusions, platelets of various shapes, channels parallel to the a-axis [100] extend perpendicular and/or cross-sections of such structures are to that plane. observed. Specifically, needles or channels lie Also in chrysoberyl, symmetry-equivalent parallel to the a-axis [100], parallel to the c-axis needle-like inclusions parallel to <011> may [001], and parallel to the edges between the be intergrown or twinned, forming angles a (100) pinacoid and the i {011} prism faces, of 60.44° and 119.56°. Flattened needles or symbolized by <011>. The cross-sections of platelets elongated parallel to the a-axis [100] flattened needles or narrow platelets elongated with cross-sections parallel to <012> may in the a-axis [100] direction are parallel to the also be intergrown, forming angles of 81.28° four edges between the a (100) pinacoid and and 98.72°.

Oriented Inclusions in Chrysoberyl 33 Feature Article

Table I: Samples of chrysoberyl varieties containing oriented inclusions.*

Sample No. polished Orientation of thin Locality Type Notes no. thin sections sections One Ti map; see also Crystal A 1 a-axis [100] Schmetzer and Malsy Lake Manyara, Tanzania; (2011) ⏊ alexandrite Two Ti maps; see also a-axis [100] Crystal B 2 Schmetzer and Bernhardt ≈ c-axis [001] ⏊ (2012) ⏊ a-axis [100] Kerala, India; alexandrite Crystal C 2 Two Ti maps ≈ c-axis [001] ⏊ Cabochon F 1 ⏊ a-axis [100] Kyocera, Japan; synthetic alexandrite (six-rayed star ⏊ See also Schmetzer et al. Cabochon G 1 b-axis [010] or cat’s-eye according to cut (2013) orientation) ⏊ Cabochon H 1 b-axis [010]

⏊ a-axis [100] Orissa, India; cat’s-eye Cabochon E 2 Perpendicular to chrysoberyl ⏊ the other section

Brazil; cat’s-eye chrysoberyl Cabochon I 1 a-axis [100]

⏊ a-axis [100] Ilakaka, Madagascar; cat’s-eye Crystal J 3 b-axis [010] chrysoberyl ⏊ c-axis [001] ⏊ ≈ b-axis [010] Sri Lanka; star chrysoberyl ⏊ Cabochon D 2 Perpendicular to Two Ti maps (four-rayed) ⏊ the other section

* Groups of similar samples are highlighted in the same colour. All thin sections were 60 µm thick except for sample A, which was 20 µm thick. the series of needles or channels causing the Materials and Methods somewhat stronger light band was oriented parallel to the a-axis [100], while the second set Samples of needles was found at a right angle to that Table I presents a summary of the samples and direction, in the bc-plane (Schmetzer, 2010). the orientation of the corresponding polished Synthetic asteriated alexandrite, on the other thin sections studied for this report. The thin- hand, shows six rays when cabochons are cut with section orientations were chosen by taking into the base perpendicular to the a-axis (Schmetzer account the size and morphology of the samples, and Hodgkinson, 2011), and the formation in combination with information available from of rutile precipitates in such crystals has been the literature (especially from author KS’s own described in numerous patent applications (see studies cited above) on the inclusion directions. the overview given by Schmetzer et al., 2013). In The crystallographic orientation of the commercially available synthetic material grown crystals, in turn, was determined by considering Kyocera, the light bands of these six-rayed stars sample morphology and optical features such are formed by three series of needles in the a as growth structures, position of the optic axes (100) plane. and pleochroism (for alexandrite). The position Consequently, the present study delves into of the crystallographic axes of the cabochon- the apparent differences between cat’s-eyes, cut samples was also established by optical four-rayed stars, and six-rayed stars, comparing examination, primarily by searching for both chatoyant and asteriated natural and synthetic optic axes with the immersion microscope. To alexandrite/chrysoberyl samples. prepare thin sections of good transparency that

34 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure 6: Alexandrite crystals and fragments from Lake Manyara frequently show a somewhat cloudy or milky appearance throughout the complete body of the samples or as alternating milky and transparent green growth zones. The tabular crystal at top-centre measures 9.6 × 6.8 mm. Daylight, photo by K. Schmetzer.

would contain sufficient oriented inclusions, a sections, based on observations of a somewhat thickness of 60 µm was selected, which is larger similar whitish appearance (Figure 7) and a than the sections typically used for petrographic specific network of inclusions seen with the studies (~25 µm). gemmological microscope. The exact source of With the goal of collecting more information this sample within the Trivandrum District is about oriented needle-like inclusions in unknown, although alexandrites from various chrysoberyl and alexandrite, the present locations in the southern Indian states of Kerala study started with crystals from Lake Manyara and Tamil Nadu have been briefly mentioned having milky-appearing areas (Figure 6) that in the literature (Menon et al., 1994; Manimaran were already known to contain such oriented et al., 2007; Fernandes and Choudhary, 2010). inclusions. Three polished thin sections from Next, again drawing upon prior work that two Lake Manyara alexandrites, which were had indicated the existence of relevant oriented previously prepared and examined by Schmet- inclusions in material grown by the Japan-based zer and Malsy (2011) and Schmetzer and company Kyocera, three polished thin sections Bernhardt (2012), were used. An alexandrite with two different orientations were added to the crystal presumably from the Trivandrum District present study; these had been prepared earlier for in Kerala, southern India, was then selected a study of cat’s-eye and star synthetic alexandrites for the preparation of two polished thin (see, e.g., Figure 8; Schmetzer et al., 2013).

Figure 7: These alexandrite crystals and fragments, Figure 8: This six-rayed asteriated synthetic alexandrite presumably from the Trivandrum District, Kerala State, produced by Kyocera weighs 1.63 ct and measures 8.3 mm southern India, show a somewhat cloudy or milky appear- in diameter. Daylight, photo by K. Schmetzer. ance. The crystal in the upper right measures 8.4 × 4.2 mm. Daylight, photo by K. Schmetzer.

Oriented Inclusions in Chrysoberyl 35 Feature Article

Figure 9: These cat’s-eye chrysoberyl cabochons, presum- Figure 10: This cat's-eye chrysoberyl from Brazil weighs ably from Orissa State, India, range from 0.54 to 1.07 ct, and 1.38 ct and measures 5.9 × 5.8 mm. Incandescent light, the smallest sample measures 5.0 × 3.7 mm. Incandescent photo by K. Schmetzer. light, photo by K. Schmetzer.

Then, operating on the premise that natural right sample in Figure 11), despite the fact that cat’s-eye and star chrysoberyl should also such samples are extremely rare and normally contain at least one or two series of needle-like not available for destructive examination. The inclusions, a cat’s-eye cabochon from a group of removal of this slice from the base did not chrysoberyls (Figure 9) presumably from the state influence the visual appearance of the stone after of Orissa, India (see Fernandes and Choudhary, cutting, and the slice was used to prepare two 2010), was selected for the preparation of two oriented polished thin sections. oriented polished thin sections. To characterize the inclusion pattern of a natural cat’s-eye chrysoberyl from a second source, Figure 11: In these four-rayed star chrysoberyls, presumably we used a transparent, high-quality cabochon from Sri Lanka, the b-axis of the crystals is almost perpen- dicular to the base of the cabochons. The weight of the (Figure 10) from one of the numerous Brazilian samples ranges from 4.49 to 10.37 ct, and the cabochon at occurrences (see, e.g., Cassedanne and Roditi, the lower right weighs 6.25 ct and measures 9.6 × 9.3 mm. 1993). This sample was sliced parallel to the sharp A slice of the cabochon in the upper right was used for the light band. preparation of two thin sections (sample D). Incandescent Because cat’s-eye chrysoberyl is also known light, photo by K. Schmetzer. from the famous gem mining area of Ilakaka, Madagascar (Milisenda et al., 2001), this study was further supplemented by a milky-appearing, only slightly translucent chrysoberyl crystal from that locality. Oriented thin sections were prepared in all three directions perpendicular to the crystal axes of this sample. Additionally, after the three slices had been removed, the edges of the remaining portion were ground and the surface was polished. The resulting irregularly shaped but rounded sample resembled a tumble-polished pebble, and a strong light band completely encircled its surface. Finally, the authors were allowed to cut a 1.9-mm-thick slice from a four-rayed star chrysoberyl cabochon from Sri Lanka (top-

36 The Journal of Gemmology, 35(1), 2016 Feature Article

Methods focus of the electron beam (~1 µm in diameter) To resolve acicular inclusions and small platelets, was used. The measurement time per pixel was all thin sections were examined at higher 140 ms, the beam current was 20 nA and the magnification (up to 1,000×) than normally acceleration voltage was 15 kV. applied in gemmology, in both reflected and Quantitative microprobe analyses of the host transmitted light, using a Leitz Ortholux II Pol- chrysoberyl also were obtained from samples BK polarizing microscope or a Leica DM LM from both localities in India (Kerala and Orissa) polarizing microscope. to further characterize material obtained from the Because previous work (especially on trade. corundum but also on some natural or synthetic The mineral phases forming the Ti-bearing chrysoberyls; see references cited above) inclusions in all of the samples were analysed by suggested that Ti-bearing phases might play an micro-Raman spectroscopy using a Horiba Jobin important role in forming acicular inclusions, Yvon XploRA PLUS confocal Raman microscope. multiple techniques were employed using a The spectrometer was equipped with a frequency- Cameca SX 50 electron microprobe to evaluate doubled Nd:YAG laser (532 nm, with a maximum the chemical nature of the inclusions. Preliminary power of 22.5 mW) and an Olympus 100× long- qualitative point analyses of individual inclusions, working-distance objective with a numerical guided by BSE images (which depict differences aperture of 0.9. The measurements were in mean atomic mass as variations in brightness performed with a 1,200 mm−1 grating, a 300 µm levels), were performed for several inclusions pinhole and a 100 µm slit. Two accumulations of that were clearly exposed at the surface of 5 sec counting time were used for each spectrum. the polished thin sections. In addition, X-ray compositional maps for Ti were obtained by Results scanning seven of the thin sections, to which a The numerous Ti-bearing needles, narrow carbon coating had been applied. BSE images of rectangular platelets, V-shaped and triangular certain scanned areas were taken as well. The Ti- platelets, and L-shaped and zigzag clusters mapped areas consisted of 512 × 512 analytical examined by micro-Raman spectroscopy points (pixels) with a step-width (point distance) in combination with microprobe analysis of 0.119 µm, which resulted in a scanned area were identified as rutile, on the basis of four of ~61 × 61 µm consisting of 262,144 points for characteristic bands at ~142 cm−1 (weak), ~239 each compositional map. To achieve the greatest cm−1 (medium), ~445 cm−1 (very strong) and ~611 possible resolution, the maximum available cm−1 (very strong) [Figure 12a; see, e.g., Porto et

Figure 12: Raman spectra are shown for a rutile inclusion in chrysoberyl from Ilakaka, Madagascar (a), and for an ilmenite inclusion in asteriated chrysoberyl from Sri Lanka (b). Spectra from the host chrysoberyl are shown for both samples for comparison.

Raman Spectra

a 611 b

683 Ilmenite inclusion 225 445 Host 370 chrysoberyl

Rutile inclusion Intensity Intensity 239 Intensity

142

Host chrysoberyl

0 100 200 300 400 500 600 700 800 900 1000 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 Wavenumber (cm–1) Wavenumber (cm–1)

Oriented Inclusions in Chrysoberyl 37 Feature Article Rare Rare Common forming L-shaped and zigzag L-shaped forming platy clusters (multiple ‘stripes’) platy clusters Elongation parallel to [100], with [100], Elongation parallel to cross-sections parallel to <012>, <012>, parallel to cross-sections Rare [001] Very rare Very Intergrown structures Intergrown parallel to parallel to Elongation <011> and <011> Rare Rare Common Common Common Common Common V-shaped or to <011>, forming forming <011>, to Elongation parallel triangular platelets Common Common Common Common rounded or rounded rectangular Cross-sections Cross-sections Larger channels Orientation of inclusions, optical microscopy

a Rare Rare ‘stripe’) elongated parallel to [100] parallel to elongated Common Cross-sections Cross-sections forming narrow narrow forming rectangles (single parallel to <012>, <012>, parallel to Single needles, channels or platelets Single needles, channels or platelets

Rare Rare <011> Common Common Common Common Common parallel to parallel to Elongation b (100) plane (100) a Single needles in Rare Rare [001] Very rare Very Common Common Common Common Common parallel to parallel to Elongation I J A E C B D no. F, G, H F, Sample s of a similar type are highlighted in the same colour. s of a similar type are highlighted alexandrite (four-rayed) chrysoberyl chrysoberyl orientation) Orissa, India; Kerala, India; Kerala, Sri Lanka; star Sri Lanka; Lake Manyara, Manyara, Lake Brazil; cat’s-eye Brazil; cat’s-eye Kyocera, Japan; Kyocera, eye according to cut to according eye Locality and variety synthetic alexandrite alexandrite synthetic cat’s-eye chrysoberylcat’s-eye chrysoberylcat’s-eye Tanzania; alexandrite Tanzania; Ilakaka, Madagascar; Ilakaka, Schmetzer and Krzemnicki, Schmetzer 2015). (six-rayed star or cat’s- (six-rayed Larger growth tubes parallel to the c-axis [001] are occasionally observed in chrysoberyl and alexandrite from various locations, but such channels were not seen in the present samples (see, e.g., seen in the present samples not are occasionally observedlocations, but such channels were in chrysoberyl various from the c-axis [001] tubes parallel to and alexandrite Larger growth Dominant inclusion Table II: Oriented needle-like inclusions or platelets in chrysoberyl inclusions or platelets needle-like varieties. II: Oriented Table a b

38 The Journal of Gemmology, 35(1), 2016 Feature Article

al., 1967]. Only the inclusions in the four-rayed star chrysoberyl from Sri Lanka were identified as ilmenite needles based on Raman bands at ~225 cm−1 (very strong), ~370 cm−1 (weak) and ~683 [001] <011> cm−1 (very strong) [Figure 12b; cf. Wang et al., 2004]. Other than for the ilmenite, the Raman spectra were all more-or-less identical and indistinguishable from the spectra for rutile available in the literature. No other crystalline

TiO2 phases were detected. Therefore, the Ti- bearing particles, which were also characterized extensively by microscopy in combination with microprobe analysis, are in general designated Figure 13: In a thin section cut perpendicular to the a-axis herein simply as rutile. of alexandrite from Lake Manyara (sample B), elongated Moreover, as a preface to describing inclusions are observed in three different orientations parallel to [001] and <011>. Some of the needles or observations for different samples in detail, it elongated inclusions parallel to <011> meet at one end, should be mentioned that additional orientations forming V-shaped angular structures or triangular platelets. of needles or platelets or of cross-sections of View parallel to the a-axis, reflected light, field of view 140 × flattened inclusions were encountered beyond 105 µm; photomicrograph by H.-J. Bernhardt. those described below, especially in the sample from Kerala, India. However, we would need to study thin sections cut in different orientations structures consisting of two intergrown needles to fully characterize these additional inclusion forming angles of ~120° were rare. Intergrown types. needles comprising crystals elongated parallel A summary of the results discussed below is to one <011> direction and parallel to the c-axis presented in Table II. [001] were not seen in the Lake Manyara material during the investigations to date. Alexandrite from Lake Manyara, Tanzania No systematic distribution for these different Alexandrite from Lake Manyara was described structures was apparent in the crystals examined. in detail by Schmetzer and Malsy (2011), and Some areas within the same crystal showed the oriented inclusions were examined by mainly single needle-like features, while other Schmetzer and Bernhardt (2012). As reported zones contained primarily angular structures of in those publications, both of the polished thin two intergrown or twinned needles/platelets. sections cut perpendicular to the a-axis showed In still other areas of the crystal, both types of needle-like to plate-like structures (Figure 4). In structures were observed together. samples A and B, three series of single elongated Qualitative point analyses of surface-reaching needles were observed in directions parallel to inclusions indicated only Ti as the main element. the c-axis [001] and parallel to <011>, forming For the compositional mapping of Ti by the angles of ~60° with each other (Figure 13). electron microprobe, areas were selected within Frequently, two needles parallel to the <011> the thin sections that in transmitted and reflected directions were intergrown or twinned, forming light showed numerous inclusions, including acute-angled, V-shaped platelets with re-entrant both single needles and intergrown structures angles measuring ~60°. Due to the differing (Figure 14a). The distribution of Ti correlated dimensions and thicknesses of the needles within well with bright spots in BSE images of the the a (100) plane, the open space between the same areas; several needles and acute-angled two sides of these V-shaped structures varied structures were observed within the surrounding widely. Some exhibited large spaces between the chrysoberyl matrix (Figure 14c,e), representing arms; others were essentially triangular platelets the section perpendicular to the a-axis, sample with almost no interstitial space. Obtuse-angled B). Weaker Ti signals corresponding to several

Oriented Inclusions in Chrysoberyl 39 Feature Article

a b

10 μm 10 μm

[001] d

<011> Ti c

10 μm

e

10 μm

Figure 14: In a thin section cut perpendicular to the a-axis of alexandrite from Lake Manyara (sample B), elongated inclusions are observed in photomicrographs in reflected light (a,b) and in transmitted light (d) compared to a Ti compositional map (c) and a BSE image (e). The scanned area measuring ~61 × 61 µm is clearly seen in reflected light due to the alteration of the carbon coating from the electron beam of the microprobe. In reflected light, the surface of the sample (a) shows rutile needles and V-shaped platelets that are also represented in the Ti compositional map (c). Focusing the optical microscope below the surface of the thin section (b) shows inclusions that generally are not seen in the Ti map. In transmitted light (d), inclusions both at the surface and below are seen. The BSE image (e) shows only rutile needles and V-shaped rutile platelets exposed at the surface of the thin section. The compositional map (c) shows Ti signals corresponding to these inclusions, as well as somewhat weaker Ti signals for inclusions located within the chrysoberyl host, but close to the surface. The scanned area (c) is outlined in (a), (b) and (d); the area of the BSE image (e) is outlined in (c); the intensity of the Ti signal in (c) ranges from weak (blue) to strong (red). Field of view ~112 × 84 µm (a,b,d); photomicrographs and Ti map by H.-J. Bernhardt.

40 The Journal of Gemmology, 35(1), 2016 Feature Article

needles and acute-angled structures also were Ti map. However, micro-Raman spectroscopy seen within the X-ray map, indicating inclusions of numerous tiny needles with this orientation not exposed at, but close to, the surface of the showed rutile spectra for some of them. Others chrysoberyl host. revealed only spectra of the chrysoberyl host, After the Ti compositional mapping was which might indicate that these needles were complete, the scanned area remained clearly simply too small for the Raman technique applied outlined in the carbon coating in reflected light or that the structures were channels. (Figure 14a,b). It was therefore possible to directly The orientation of the thin section cut compare the microscopic view in transmitted/ almost perpendicular to the c-axis (Figure 5) is reflected light with the BSE image (Figure 14e) a rectangular slice through the section shown and the Ti compositional map (Figure 14c). in Figures 13 and 14. If rutile needles with a When the optical microscope was focused on the thickness in the micrometre range (see above) surface of the sample (Figure 14a), the pattern are cut in such a way, their representation on of inclusions observed in reflected light closely the Ti map would be single points. If triangular resembled that seen in the BSE image, and these rutile platelets are cut in this way, the Ti map inclusions provided relatively strong Ti signals in would show small lines. Both types of reflective the compositional map (Figure 14c). However, if structures were identified as rutile by Raman the optical microscope was focused some microns spectroscopy. further below the surface, a completely different The lack of any Ti-related features in the inclusion picture was revealed in reflected light, compositional map corresponding to the tiny consisting of needles and platelets located needle-like structures running parallel to the entirely within the chrysoberyl host (Figure 14b). a-axis [100] indicates either (1) that any Ti signals Most of these inclusions were not indicated in from these inclusions were below the resolution the Ti map. In transmitted light, a denser pattern of the microprobe, if in fact these needles were of inclusions was visible (Figure 14d) that could rutile and exposed to the surface, or (2) that thus be characterized as an overlap or summation only channels were present. Nonetheless, the of the inclusions seen in reflected light at various Raman examination showed, at least for some of depths within the polished thin section. All these small needles, that they were indeed rutile. these needles or platelets proved to be rutile by Consequently, the presence of tiny rutile needles Raman analysis, with the individual needles or parallel to the a-axis [100] was established, but platelets having—in the direction of the a-axis—a the additional presence of channels in the same thickness in the range of 1–2 µm or even smaller. direction could not be ruled out. The microscopic features of the thin section of The observations from optical microscopy, sample B that was cut almost perpendicular to the BSE imaging and Ti compositional mapping for c-axis revealed two principal types of inclusions: sample A from Lake Manyara, obtained from (1) those concentrated in planes perpendicular a thin section cut perpendicular to the a-axis, to the a-axis, and (2) tiny needle-like structures, generally showed results similar to those of sometimes slightly flattened, running parallel to sample B with the same orientation and therefore the a-axis [100] (Figure 5). For the former type are not repeated here. Additionally, in one area of inclusions, the BSE image depicted numerous of the thin section, cross-sections of needles or single bright spots, and occasionally somewhat channels elongated parallel to the a-axis [100] elongated points or short lines. The compositional were observed (Figure 15), appearing in this map also showed a high concentration of Ti orientation as parallel lines comprising individual in these areas. Raman spectroscopy of several somewhat rounded structures. In reflected light, highly reflective particles with almost square or some of these structures were highly reflective rectangular (sometimes slightly rounded) cross- and could be identified as rutile by Raman sections yielded clear rutile spectra. spectroscopy. However, as with the results Conversely, the needle-like structures running just described for sample B, it is possible that parallel to the a-axis [100]—the second type of channels having the same orientation might also inclusions—were not clearly resolved in the be present.

Oriented Inclusions in Chrysoberyl 41 Feature Article

17b). The Ti map (Figure 17c), which represented only the surface of the thin section, registered three relatively large rutile needles within the chrysoberyl host. Transmitted light provided a composite view of inclusions at multiple depths within the sample (Figure 17d). Several of these inclusions were identified as rutile by micro- Raman spectroscopy. Most of the rutile needles were elongated parallel to the <011> directions of the host (Figures 17 and 18). Needles parallel to the c-axis [001] were occasionally present, but less commonly than in the Lake Manyara material. Figure 15: Cross-sections of several sequences of needle-like Moreover, the needles and platelets in the sample inclusions are seen in a thin section cut perpendicular to from Kerala were larger than in material from the a-axis, in alexandrite from Lake Manyara (sample A). The Lake Manyara, although they, too, were up to 1–2 individual somewhat rounded cross-sections form numerous µm thick in the direction parallel to the a-axis parallel lines. Some of these inclusions are highly reflective and were identified as cross-sections of rutile needles. [100]. The pleochroism, as observed in different Reflected light, crossed polarizers, field of view 167 × 125 parts of the rutile platelets or V-shaped rutile µm; photomicrograph by H.-J. Bernhardt. crystals (Figures 18 and 19), established that the inclusions consisted of two different parts with Alexandrite from Kerala, India different crystallographic orientations. Alexandrite from Trivandrum in the Kerala State of southern India has been mentioned in the Figure 16: Observed parallel to the a-axis (as shown by literature, but a detailed description is unknown inset), an alexandrite from Kerala State, India, reveals a to the present authors. The material available for dense network of needle-like structures parallel to the this study comprised primarily broken crystal <011> directions. Immersion, field of view 2.7× 3.6 mm; photomicrograph by K. Schmetzer. fragments, along with a few complete crystals and some tabular contact twins. Microprobe analyses of six samples of this alexandrite yielded

0.25–0.85 wt.% Cr2O3, 0.03–0.05 wt.% V2O3 and

0.81–1.35 wt.% Fe2O3. In the gemmological microscope, most samples showed a distinct network of fine needle-like inclusions oriented parallel to the <011> directions (Figure 16). Furthermore, a dense series of needles or channels parallel to the a-axis [100] was present in most samples. A similar inclusion pattern has been described for some alexandrite from Sri Lanka and Madagascar (Schmetzer, 2010). Examination of the two polished thin sections at higher magnification, in combination with Ti compositional mapping by electron microprobe, showed a number of similarities with the Lake Manyara material. In the thin section oriented −i i perpendicular to the a-axis, Ti-bearing needles or c platelets were present, and the inclusion pattern b a differed substantially depending on whether the focus was at the surface of the thin section b (Figure 17a) or slightly below the surface (Figure

42 The Journal of Gemmology, 35(1), 2016 Feature Article

a b

10 μm 10 μm

d

Ti c [001]

<011> 10 μm 10 μm

Figure 17: An alexandrite from Kerala (sample C), cut perpendicular to the a-axis, is shown in reflected (a,b) and transmitted light (d) compared to the Ti compositional map (c). In reflected light, the view of the surface of the sample (a) shows the scanned area (measuring ~61 × 61 µm), with rutile needles that are also represented in the Ti distribution map (c). Focusing the optical microscope slightly below the surface of the thin section with crossed polarizers shows inclusions (b) that generally are not observed in the Ti distribution map. In transmitted light (d), inclusions both at the surface and at various depths below the surface are seen. The scanned area (c) is outlined in (a), (b) and (d); the intensity of the Ti signal in (c) ranges from weak (blue) to strong (red). Field of view ~112 × 84 µm; photomicrographs and map by H.-J. Bernhardt.

Figure 18: An alexandrite crystal from Kerala, cut perpendicular to the a-axis (sample C), shows elongated rutile inclusions in different orientations parallel to <011>. Some of them meet at one end, forming V-shaped angular [001] <011> structures or platelets; single needles parallel to the c-axis are only rarely seen. View parallel to the a-axis, reflected light, crossed polarizers, field of view 224 × 160 µm; photomicrograph by H.-J. Bernhardt.

Oriented Inclusions in Chrysoberyl 43 Feature Article

a b c

Figure 19: Somewhat larger V-shaped or triangular rutile platelets in the alexandrite from Kerala, cut perpendicular to the a-axis (sample C), are shown in these images (a, b and c). View parallel to the a-axis, reflected light, crossed polarizers, field of view 112 × 84 µm; photomicrographs by H.-J. Bernhardt.

More atypically, in one area of the Kerala thin two needles were intergrown or if they were merely section cut perpendicular to the a-axis, structures exsolved at different depths close to each other and appearing as short lines were observed parallel thereby overlapped in the microscopic view of the to the <012> directions of the chrysoberyl host, thin section. The needles were too small for either and were often connected to form L-shaped or zigzag patterns (Figure 20). Such an orientation Figure 20: In this area of the Kerala alexandrite thin section was recently described in a chrysoberyl from shown in Figures 18 and 19, cross-sections of elongated Brazil (Drev et al., 2015). In the Kerala sample, inclusions are observed in different orientations parallel to <012>. Some of these structures meet, forming L-shaped these inclusions also were identified as rutile by or zigzag patterns. View parallel to the a-axis, reflected light Raman spectroscopy. As further explained below (top), reflected light and crossed polarizers (bottom), field of in connection with the Orissa material, these view 112 × 84 µm; photomicrographs by H.-J. Bernhardt. structures represented cross-sections of platelets elongated parallel to the a-axis [100]. The other thin section of the alexandrite from Kerala, cut with an orientation almost perpendicular to the c-axis, showed needle-like structures of different lengths, and the compositional map recorded simply Ti-bearing spots or somewhat elongated Ti-rich areas. Again, these are the typical patterns expected if needles or V-shaped platelets such as those depicted in Figures 17–19 are cut at a right angle to the a (100) face.

Kyocera Synthetic Alexandrite <012> Asteriated and chatoyant synthetic alexandrites from Kyocera in Japan were described in detail by Schmetzer and Hodgkinson (2011) and by Schmetzer et al. (2013). The thin section of this Ti-bearing material oriented perpendicular to the a-axis (sample F) showed small elongated particles in three directions, with the three series of needles forming angles of ~60° with each other (Figure 21a). Several intergrown particles were seen, mostly with re-entrant angles of 60° and rarely with angles of 120° (Figure 21b). However, due to the small size of these particles and the dense pattern, it was sometimes difficult to determine if

44 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure 21: A thin section cut perpendicular a to the a-axis of a synthetic asteriated alexandrite grown by Kyocera (sample F) shows a dense network of needles oriented in the <011> and [001] dir- ections. In general, isolated needles or needles that are intergrown forming an angle of ~60° are observed (a), whereas two needles forming an angle of 120° (b, indicated by arrows) are less common. Reflected light, field of view 112 x 84 µm; photomicrographs by H.-J. Bernhardt.

b

microprobe analyses or micro-Raman spectroscopy. a previous study, some samples described The examination of samples G and H, both cut as colour-change chrysoberyl showed low perpendicular to the b-axis, did not reveal additional concentrations of both V and Cr in comparable information, only corroborating what was learned amounts (Schmetzer, 2010). from sample F. For further details, the reader is The chatoyant chrysoberyl selected for the referred to the publications cited above. present study (sample E) was chosen from a group of cabochons (e.g. Figure 9) that were Chatoyant Chrysoberyl from Orissa, India slightly greenish grey in daylight and grey Cat’s-eye chrysoberyl from Orissa has been in incandescent light. Four samples from the known in the trade for several years. The group were analysed by electron microprobe, faceted chrysoberyl and alexandrite, as well as which recorded 0.05–0.07 wt.% V2O3, 0.03–0.05 their chatoyant varieties, frequently have a low- wt.% Cr2O3, and 0.45–0.61 wt.% Fe2O3. These saturation greenish or a light greyish colour in measurements are comparable with published daylight, with a colour change to grey or light data for faceted material from Orissa (Schmetzer, purple, respectively, in incandescent light. In 2010).

Oriented Inclusions in Chrysoberyl 45 Feature Article

a c

<012>

b d [001]

<011>

Figure 22: Photomicrographs in reflected light (a,c,d) and in reflected light with crossed polarizers (b) of a thin section cut perpendicular to the a-axis of a cat’s-eye chrysoberyl from Orissa (sample E) show a network of L-shaped or zigzag cross- sections of rutile platelets parallel to <012> (a,b). Only a few cross-sections oriented parallel to <011> are observed in one small area of the thin section (c,d; indicated by arrows). Field of view 112 × 84 µm; photomicrographs by H.-J. Bernhardt.

The thin section from sample E (cut by the linear structures. It was further seen that perpendicular to the a-axis and parallel to the the different narrow parts of these complex light band of the cabochon) showed a network platelets came into focus at different depths, of reflective rectangular structures parallel to the <012> directions of the host chrysoberyl (Figure Figure 23: Chrysoberyl cat’s-eye from Orissa (sample E) 22a,b). Typically, two, three or even more of shows a dense network of complex rutile platelets elongated these inclusions were linked together, forming an parallel to the a-axis. The platelets are composed of multiple L-shaped or zigzag pattern. In one area of this thin narrow parts or ‘stripes’ that are inclined to each other and section, similar structures parallel to the <011> intergrown. Linear junctions connecting these parts or ‘stripes’ are also oriented parallel to the a-axis. Transmitted light, field directions were also observed (Figure 22c,d). of view 225 × 168 µm; photomicrograph by H.-J. Bernhardt. Numerous examples of both types of inclusions revealed Raman spectra for rutile. The thin section cut perpendicular to that just described showed a dense network of what appeared to be linear structures elongated parallel to the a-axis [100]. This pattern was best seen in transmitted light (Figure 23). Upon detailed a-axis inspection, it was observed that typically two or three, but occasionally more, of these linear structures existed within a somewhat larger platy inclusion. The linear structures traversed the larger platelet and gave it the appearance of being comprised of multiple narrow parts, connected

46 The Journal of Gemmology, 35(1), 2016 Feature Article

a b c

Figure 24: A dense network of complex platelets with internal linear junctions oriented parallel to the a-axis is shown in a cat’s-eye chrysoberyl from Orissa (sample E). The small rutile platelets consisting of several parts or ‘stripes’ each reflect and scatter light. Transmitted light (a), reflected light (b) and reflected light with crossed polarizers (c), field of view 112 × 84 µm; photomicrographs by H.-J. Bernhardt. indicating that they were inclined to the plane scattered the incident illumination (Figure 24). of the polished thin section. Many such platelets When the chrysoberyl was cut as a cabochon, it were examined by micro-Raman spectroscopy was this scattered and reflected light that formed and showed rutile spectra. the bright band of the cat’s-eye. Taking into consideration the observations of both the slice cut perpendicular to the a-axis (Figure Chatoyant Chrysoberyl from Brazil 22) and the slice cut parallel to the a-axis [100] (Figure In the immersion microscope, the transparent 23), it was concluded that the L-shaped and zigzag cat’s-eye chrysoberyl from Brazil revealed a dense patterns of rectangular rutile particles along <012> pattern of needles with an orientation parallel to depicted in Figure 22 represented cross-sections of the a-axis [100]. These oriented needles visually the platy inclusions with internal linear structures resembled the inclusion scenario seen in the elongated parallel to the a-axis [100] depicted in alexandrite from Lake Manyara in Figure 2. In Figure 23. As such, the linear structures along the the polished thin section cut perpendicular to a-axis [100] and at right angles to the L-shaped and the needle axis, numerous highly reflective cross- zigzig patterns represented the junctions between sections of such needles could be observed the different parts of the larger platy rutile inclusions. (Figure 25). These were determined to be rutile Moreover, taking into account the description by Drev et al. (2015) of rectangular structures along Figure 25: Cat’s-eye chrysoberyl from Brazil (sample I) <012> as intergrown rutile clusters, it could further is shown here in transmitted light in a thin section cut be concluded that: (1) the larger platy inclusions perpendicular to the a-axis. The photo shows cross-sections or complex platelets described above were rutile of rutile needles elongated parallel to [100], together with clusters, and (2) the linear structures elongated a few needles and V-shaped platelets elongated parallel to <011>; some needles along [001] are also observed. Field parallel to the a-axis [100] represented the edges of view 150 × 112 µm; photomicrograph by H. A. Gilg. or interconnections between the different inclined parts of the platy clusters. In other words, the platy rutile clusters were composed of narrow inclined sections elongated parallel to the a-axis [100] that caused the platelets to appear ‘striped’ when viewed perpendicular to the a-axis. When viewed in cross-section, two such narrow intergrown ‘stripes’ formed the L-shaped pattern parallel to the <012> directions of the host, while more than two such ‘stripes’ formed the zigzag pattern, likewise parallel to the <012> directions. When lit from above, the different parts or ‘stripes’ of the platy rutile clusters reflected and

Oriented Inclusions in Chrysoberyl 47 Feature Article

by micro-Raman spectroscopy. Likewise seen elongated parallel to the a-axis [100] (Figures were a few needles and V-shaped platelets with 26 and 27). As explained above for the Orissa an orientation parallel to the a-plane (100), and sample, the narrow platelets elongated parallel again Raman examination identified them as to the a-axis [100] had rectangular cross-sections rutile. parallel to <012>. In the Madagascar sample, however, only a few of these inclusions were Chatoyant Chrysoberyl from intergrown, and L-shaped cross-sections were Ilakaka, Madagascar rare. Applying the descriptions used for the Cat’s-eye chrysoberyl from Ilakaka is mostly Orissa sample, the platelets elongated parallel seen in the trade as cabochons prepared from to the a-axis [100] in the Ilakaka stone might be high-quality transparent material; in addition, characterized as representing only one narrow samples with a milky appearance are known. part or ‘stripe’. One such slightly waterworn crystal (sample J), The thin sections cut perpendicular to the which showed a clear morphology consisting b- and c-axes both showed a similar inclusion of the pinacoids a (100) and b (010) in pattern of narrow platelets elongated parallel combination with i {011} prism faces and o {111} to the a-axis [100], consisting of a single part or dipyramids, was selected for the preparation of ‘stripe’ each, and cross-sections of the needles three polished thin sections perpendicular to and platelets oriented parallel to the a-plane the three crystallographic axes a, b and c. As (100) (Figure 28). Micro-Raman spectroscopy noted previously, the part of the Ilakaka crystal of numerous inclusions of all the types just remaining after removal of these slices was mentioned showed spectra for rutile. ground and polished into a rounded, irregularly shaped specimen, which displayed a bright, Asteriated Chrysoberyl from Sri Lanka reflective light band encircling the sample. Star chrysoberyl from Sri Lanka has been The thin section cut perpendicular to the mentioned in the gemmological literature as a-axis showed an inclusion scene consisting of an extremely rare phenomenal gemstone. needles and V-shaped platelets parallel to the Subsequent to a previous study dealing with four- a-plane (100) and cross-sections of platelets rayed chrysoberyl (Schmetzer, 2010), the first author was able to examine six additional four- rayed star samples of varying quality (e.g. Figure Figure 26: This view of a chrysoberyl from Ilakaka, 11). Such asteriated chrysoberyls are frequently Madagascar (sample J), in a thin section cut perpendicular to the a-axis, shows the inclusion pattern and a cross- heavily included and only translucent. However, it cutting healed . The chrysoberyl host shows a high was possible by optical examination (correlation concentration of rutile needles and platelets, whereas the of the crystal orientation with the positions of area within the healed fracture is free of rutile particles and both optic axes) to determine the location of the shows only some larger fluid inclusions trapped during the b-axis [010] in four of these six samples as being healing process. Transmitted light, field of view 300 × 222 more-or-less at the centre of the stars. Together µm; photomicrograph by H. A. Gilg. with samples examined previously, this optical orientation in four-rayed star chrysoberyls has now been established for a total of six samples. These results indicate an orientation of two series of needles or channels perpendicular to this axis in the ac-plane. The slice examined for the present study (sample D) had been cut from, and parallel to, the flat base of such a four-rayed star chrysoberyl (top-right in Figure 11). As stated earlier, two thin sections were prepared from the slice, perpendicular to each other. The slight inclination of the arms of the star was a consequence of

48 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure 27: The Ilakaka sample in a Figure 26 is shown here in transmitted light (a) and in transmitted light with crossed polarizers (b). Evident is a high concentration of rutile platelet cross- sections elongated parallel to <012>, together with needles and V-shaped [001] platelets elongated parallel to <011>; some needles along [001] are also observed. Field of view 83 × 62 µm; photomicrographs by H. A. Gilg.

<011>

b

<012>

the b-axis [010] being inclined by about 30° in did not reflect any Ti concentrations for these relation to the base of the cabochon. Upon tilting particles, and the electron microprobe did not the cabochon by approximately that angle, the record high concentrations of other elements that four-rayed star became orthogonal. Microscopic examination of the thin section Figure 28: In a thin section cut perpendicular to the c-axis, the cut parallel to the base of the cabochon showed Ilakaka chrysoberyl (sample J) shows a high concentration two series of inclusions oriented parallel to the of rutile platelets and needles elongated parallel to the a-axis. Most of the platelets consist of only a single part a-axis [100] and parallel to the c-axis [001] (Figure or ‘stripe’. Transmitted light, field of view 150 × 112 µm; 29a,b,d). The series parallel to the c-axis [001] photomicrograph by H. A. Gilg. was highly reflective and showed Ti signals in the compositional map (Figure 29c). Unexpectedly, micro-Raman spectroscopy of several of these elongated inclusions did not show the pattern for rutile, but instead a spectrum assigned to ilmenite, FeTiO3. The series of needles or channels parallel to the a-axis [100] was not reflective when viewed a-axis in the polarization microscope. If the thin section was rotated so the chrysoberyl appeared dark between crossed polarizers, these elongated particles also invariably appeared dark. Hence, they seemed to show no birefringence. Furthermore, the compositional map (Figure 29c)

Oriented Inclusions in Chrysoberyl 49 Feature Article

a b

10 μm

d

Ti c

[100]

[001]

10 μm 10 μm

Figure 29: A thin section of an asteriated chrysoberyl from Sri Lanka (sample D), representing a section approximately perpendicular to the b-axis, is shown in reflected light (a) and in reflected light with crossed polarizers (b,d) compared to a Ti compositional map (c). In reflected light, focusing on the surface of the sample (a) shows the scanned area (measuring ~61 × 61 µm), with one series of parallel ilmenite needles that are also represented on the Ti distribution map (c); a second series of needles or channels perpendicular to the first series shows no Ti. The intensity of the Ti signal in (c) ranges from weak (blue) to strong (red). Field of view 112 × 84 µm (a,d) and 224 × 168 µm (b); photomicrographs and map by H.-J. Bernhardt. could suggest the presence of an alternative type rectangular cross-sections of the ilmenite needles. of elongated inclusion. In addition, micro-Raman The compositional map depicted numerous spectroscopy showed only the Raman lines of the corresponding spots with high Ti concentration. chrysoberyl host. Consequently, these elongated These data confirm the results described above inclusions along the a-axis [100] might represent that were obtained from the thin section oriented channels. Nonetheless, given the small size parallel to the base of the cabochon. of rutile precipitates in a Brazilian chrysoberyl found by Drev et al. (2015) through use of a Discussion and Conclusions transmission electron microscope, there remains The combination of immersion microscopy the possibility that similarly minute rutile needles of gem materials at low magnification, optical might be present in the star chrysoberyl from Sri microscopy of polished thin sections cut in Lanka that did not generate conclusive signals preferred orientations at high magnification, with our instruments. micro-Raman spectroscopy and electron The thin section cut perpendicular to the microprobe techniques (qualitative point base of the asteriated cabochon revealed only analysis, BSE imaging and Ti compositional a few highly reflective and somewhat rounded mapping) showed that two primary groups of inclusions, which may be understood as the rutile inclusions existed in the chrysoberyl and

50 The Journal of Gemmology, 35(1), 2016 Feature Article

alexandrite samples examined for this study. four-rayed star chrysoberyl, elongated ilmenite Their concentrations varied among the different particles were seen parallel to the c-axis [001]. sources. One group was characterized by Also present were needle-like inclusions parallel needles and platelets on planes perpendicular to the a-axis [100] that could not be identified as to the a-axis, whilst the other group consisted of mineral inclusions by the methods applied. This needles and platelets elongated parallel to the latter type may consist of channels or minute a-axis [100]. More specifically: rutile needles. 1. In one group, three different series of In samples A and B from Lake Manyara, needle-like to flat tabular rutile inclusions Tanzania, and in sample C from Kerala, India, the oriented in planes parallel to the a (100) rutile platelets or needles located in the a (100) pinacoid were found in natural as well as plane were highly reflective and birefringent, and synthetic samples. These rutile needles caused the samples to appear whitish in a view were elongated parallel to the c-axis [001] parallel to the a-axis [100], i.e. perpendicular and along symmetry-equivalent <011> to the triangular rutile platelets, flattened rutile directions. Frequently, V-shaped rutile needles or V-shaped rutile structures. These platelets with re-entrant angles of ~60°, small needles or platelets with a thickness in the rarely ~120°, and/or triangular rutile a-axis [100] direction in the micrometre range (or platelets were formed by such flattened even smaller) were distributed throughout the rutile needles and platelets. completely milky-appearing crystals or within the 2. In the other group, rutile needles and cloudy areas of zoned samples. platelets consisting of one or more narrow If such inclusions are not exposed at the rectangular parts or ‘stripes’ elongated surface of a crystal or a polished thin section, in directions parallel to the a-axis [100] they still reflect light and are clearly visible in were observed. In the optical microscope, the microscope. They generally do not, however, the rutile needles showed rectangular, contribute to the intensity of the Ti signal recorded somewhat rounded cross-sections. Rutile by the detector of the electron microprobe. As platelets consisting of only a single part a result, previous studies (Schmetzer and Malsy, or ‘stripe’ showed rectangular cross- 2011; Schmetzer and Bernhardt, 2012) are not sections parallel to the <012> directions inconsistent with the present, more complete of the host. More complex platelets work employing multiple techniques. were formed by clusters of intergrown Although the Ti-bearing needles or platelets in and inclined rutile parts or ‘stripes’, with samples from Lake Manyara and Kerala showed a internal linear junctions elongated parallel somewhat cloudy, milky appearance in reflected to the a-axis [100] direction. Cross-sections light, no sharp six-rayed asteriated chrysoberyls of such complex platelets were oriented have been reported to date from these two areas. along several symmetry-equivalent <012> The presence of both needles and platelets, directions, with re-entrant angles of ~81° or combined with the relatively large dimensions of ~99° formed by the different parts of these these inclusions, prevents such a phenomenon. clusters. These cross-sections displayed an Conversely, synthetic asteriated alexandrite from L-shaped or zigzag pattern. Kyocera showed a dense network consisting of The inclusion pattern seen in any given three series of distinctly smaller needles in the alexandrite or chrysoberyl, as demonstrated by same orientations as in the Lake Manyara and various samples in this study (see, e.g., Figure Kerala examples, but no larger platelets were seen 3), may represent both of these groups, that in the synthetic alexandrite. Thus, the Kyocera is needles or V-shaped platelets on planes synthetics, when cut as cabochons with the base perpendicular to the a-axis, and needles or parallel to the a (100) pinacoid (e.g. sample F in platelets elongated parallel to the a-axis [100]. the present study) showed six-rayed asterism. If These primary groups may also be augmented the base of a synthetic alexandrite cabochon was by further types of inclusions. For instance, in the different from this particular orientation (samples

Oriented Inclusions in Chrysoberyl 51 Feature Article

G and H), only one light band was commonly for the milky appearance of such samples in all observed, and such samples are described in the directions perpendicular to the a-axis. Given that trade as synthetic cat’s-eye alexandrite. larger c (001) faces are extremely rare in natural Perpendicular to the a (100) plane (i.e. chrysoberyl or alexandrite, a whitish appearance parallel to the a-axis [100]), larger channels or is normally visible in a view toward the b (010) needles of sufficient size to be resolved with the pinacoid or the i {011} prism faces, which are magnification of the gemmological microscope frequently well developed in chrysoberyl. were seen in a previous study of samples from Complex rutile platelets formed by various Lake Manyara (Figure 2), and now also in the narrow intergrown parts or ‘stripes’ elongated cat’s-eye chrysoberyl from Brazil (sample I) and parallel to the a-axis [100], with L-shaped or in the alexandrite crystals from Kerala. Smaller zigzag cross-sections along the <012> directions, elongated particles with the same orientation were were observed in the cat’s-eye chrysoberyl from found in samples A and B from Lake Manyara Orissa, India (sample E). The internal edges or and in sample D, the asteriated chrysoberyl from junctions between the inclined parts or ‘stripes’ Sri Lanka. likewise ran along the a-axis [100]. These The particles along the a-axis [100] in the complex platy structures represent a previously four-rayed star chrysoberyl from Sri Lanka undocumented type of inclusion as well as a new could not definitively be identified as rutile mechanism for forming the light band in cat’s-eye by optical examination in combination with chrysoberyl. The same type of inclusion also was electron microprobe analysis and micro-Raman observed in a small area within the thin section spectroscopy. These inclusions are therefore of alexandrite from Kerala, India (sample C). possibly elongated channels, although it must Furthermore, elongated rutile platelets consisting be considered that very small rutile needles of of only one narrow part or ‘stripe’ each, with the size described by Drev et al. (2015) would simple rectangular cross-sections, were found in probably not be seen with the methods applied high concentration in sample J from Madagascar. in the present study. The sizes of the rutile inclusions with a similar In contrast, rutile spectra were recorded for orientation as described by Drev et al. (2015), numerous tiny needles parallel to the a-axis [100] for a section perpendicular to the a-axis in one in samples A and B from Lake Manyara, for both chrysoberyl from Brazil, were much smaller. elongated needles (sample B) and cross-sections In both chrysoberyls with a high concentration of needles (sample A). Similar cross-sections of of rutile platelets (samples E and J), chatoyancy rutile needles also were positively identified in the was observed in the direction perpendicular to cat’s-eye chrysoberyl from Brazil. Consequently, at the elongation of the platelets. These platelet- least a subset of particles elongated parallel to the derived light bands correspond to those formed a-axis [100] can be characterized as rutile needles. by needles in certain other chatoyant chrysoberyls If a dense concentration of such minute such as sample I from Brazil. particles (channels and/or rutile needles) If both types of inclusions are present—that elongated along the a-axis [100] is present, these is, rutile platelets or flattened needles in thea structures cause a light band with an orientation (100) plane and a dense network of channels perpendicular to the needle axis. Such a light and/or rutile needles/platelets elongated in the band formed the chatoyancy in the cat’s-eye a-axis [100] direction—then the crystal appears chrysoberyl from Brazil and was one of the bands somewhat whitish in most directions, as observed observed in four-rayed asteriated chrysoberyl for sample B from Lake Manyara and especially from Sri Lanka (sample D). The second light band for sample J from Ilakaka, Madagascar. This in the Sri Lankan star studied here was generated indicates that a whitish appearance in alexandrite by ilmenite needles along the c-axis [001]. or chrysoberyl is caused by more than one In crystals from Lake Manyara or Kerala, the mechanism, and the direction of view parallel scattering of light by these elongated inclusions or perpendicular to the a-axis allows these (channels and/or rutile needles) was responsible mechanisms to be distinguished.

52 The Journal of Gemmology, 35(1), 2016 Feature Article

References 394, http://dx.doi.org/10.15506/jog.2001.27.7. 385. Cassedanne J. and Roditi M., 1993. The location, Moon A.R. and Phillips M.R., 1991. Titania precipitation geology, mineralogy and gem deposits of in sapphire containing iron and Ti. Physics and alexandrite, cat’s-eye and chrysoberyl in Brazil. Chemistry of Minerals, 18(4), 251–258, http:// Journal of Gemmology, 23(6), 333–354, http:// dx.doi.org/10.1007/bf00202577. dx.doi.org/10.15506/jog.1993.23.6.333. Phillips D.S., Heuer A.H. and Mitchell T.E., Drev S., Komelj M., Mazaj M., Daneu N. and Recˇ nik A., 2015. Structural investigation of (130) twins 1980. Precipitation in star sapphire. I. and rutile precipitates in chrysoberyl crystals from Identification of the precipitate. Philosophical Rio das Pratinhas in Bahia (Brazil). American Magazine A, 42(3), 385–340, http://dx.doi. Mineralogist, 100(4), 861–871, http://dx.doi. org/10.1080/01418618008239365. org/10.2138/am-2015-5120. Porto S.P.S., Fleury P.A. and Damen T.C., 1967. Raman spectra of TiO , MgF , ZnF , FeF , and MnF . Eppler W.F., 1958. Notes on asterism in spinel and 2 2 2 2 2 chatoyancy in chrysoberyl, quartz, tourmaline, Physical Review, 154(2), 522–526. zircon and . Journal of Gemmology, Schmetzer K., 2010. Russian Alexandrites. 6(6), 251–263, http://dx.doi.org/10.15506/jog. Schweizerbart Science Publishers, Stuttgart, 1958.6.6.251. Germany, 141 pp. Fernandes S. and Choudhary G., 2010. Understanding Schmetzer K. and Bernhardt H.-J., 2012. Oriented Rough Gemstones. Indian Institute of Jewellery, inclusions in alexandrite from the Lake Manyara Mumbai, 211 pp. deposit, Tanzania. Australian Gemmologist, He J., Lagerlof K.P.D. and Heuer A.H., 2011. Structural 24(11), 267–271. evolution of TiO precipitates in Ti-doped Schmetzer K. and Hainschwang T., 2012. Origin 2 determination of alexandrite – A practical sapphire (α-Al2O3). Journal of the American Ceramic Society, 94(4), 1272–1280, http://dx.doi. example. InColor, 21, 36–39. org/10.1111/j.1551-2916.2010.04217.x. Schmetzer K. and Hodgkinson A., 2011. Synthetic star Kumaratilake W.L.D.R.A., 1997. : A alexandrite. Gems&Jewellery, 20(3), 9–11. list of cat’s-eyes and stars. Journal of Gemmology, Schmetzer K. and Krzemnicki M.S., 2015. Nail- 25(7), 474–482, http://dx.doi.org/10.15506/jog. head spicules as inclusions in chrysoberyl from 1997.25.7.474. Myanmar. Journal of Gemmology, 34(5), 434–438, Langensiepen R.A., Tressler R.E. and Howell P.R., http://dx.doi.org/10.15506/jog.2015.34.5.434. 1983. A preliminary study of precipitation in Schmetzer K. and Malsy A.-K., 2011. Alexandrite and Ti4+-doped polycrystalline alumina. Journal of colour-change chrysoberyl from the Lake Manyara Materials Science, 18(9), 2771–2776, http:// alexandrite-emerald deposit in northern Tanzania. dx.doi.org/10.1007/bf00547594. Journal of Gemmology, 32(5–8), 179–209, http:// Manimaran G., Bagai D. and Chacko P.T.R., 2007. dx.doi.org/10.15506/jog.2011.32.5.179. Chrysoberyl from southern Tamil Nadu of Schmetzer K., Bernhardt H.-J. and Hainschwang, South India, with implications for Gondwana T., 2013. Ti-bearing synthetic alexandrite and studies. In S. Rajendran, S. Aravindan and K. chrysoberyl. Journal of Gemmology, 33(5–6), Srinivasamoorthy, Eds., Mineral Exploration, New 137–148, http://dx.doi.org/10.15506/jog.2013.33. India Publishing Agency, New Delhi, 63–76. 5.137. Marder J.M. and Mitchell T.E., 1982. The nature of Viti C. and Ferrari M., 2006. The nature of Ti- precipitates in cat’s-eye chrysoberyl. 40th Annual rich inclusions responsible for asterism in Meeting of Electron Microscopy Society of America, Verneuil-grown . European Journal 1982, Washington DC, USA, 556–557. of Mineralogy, 18(6), 823–834, http://dx.doi. McClure S.F. and Koivula J.I., 2001. A new method org/10.1127/0935-1221/2006/0018-0823. for imitating asterism. Gems and Gemology, Wang A., Kuebler K.E., Jolliff B.L. and Haskin L.A., 37(2), 124–128, http://dx.doi.org/10.5741/gems. 2004. Raman spectroscopy of Fe-Ti-Cr-, 37.2.124. case study: Martian meteorite EETA79001. Menon R.D., Santosh M. and Yoshida M., 1994. American Mineralogist, 89(5–6), 665–680, http:// Gemstone mineralization in southern Kerala, dx.doi.org/10.2138/am-2004-5-601. India. Journal of the Geological Society of India, Xiao S.Q., Dahmen U. and Heuer A.H., 1997. Phase

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The Authors Acknowledgements Dr Karl Schmetzer FGA Samples for this study, other than those D-85238 Petershausen, Germany taken from the personal collection of one of Email: [email protected] the authors (KS), were kindly provided by the late George Bosshart (Horgen, Switzerland), Dr Heinz-Jürgen Bernhardt Dr Thomas Hainschwang (Balzers, ZEM, Institut für Geologie, Mineralogie und Liechtenstein), Alan Hodgkinson (Portencross, Geophysik, Ruhr-University Bochum Scotland), Dr Jaroslav Hyršl (Prague, Czech D-44780 Bochum, Germany Republic), Dr Michael S. Krzemnicki (from the Henry A. Hänni collection housed at Prof. Dr H. Albert Gilg the Swiss Gemmological Institute SSEF, Lehrstuhl für Ingenieurgeologie Basel, Switzerland) and Martin P. Steinbach Technische Universität München (Idar-Oberstein, Germany). The technical D-80333 Munich, Germany laboratories at Bochum and München Universities are also thanked for the careful preparation of the polished thin sections.

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54 The Journal of Gemmology, 35(1), 2016 ORIGIN DETERMINATION · TREATMENT DETECTION

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The Great Mughal and the Orlov: One and the Same Diamond?

Anna Malecka

One of the most famous stones mentioned in the gemmological literature is the so-called Great Mughal diamond, described and depicted in a 17th-century work of Jean-Baptiste Tavernier. According to Tavernier, this specimen weighed ~286 metric carats (upon recalculation from Eastern units); it was not mentioned in later sources referring to the Mughal court. In the 18th century, however, a diamond reminiscent of the Great Mughal appeared on the market—it is known today as the Orlov (189.62 ct). Some researchers have suggested that these specimens could be identical, if not for the fact that the Orlov weighs about 90 ct less than the stone reported by Tavernier. This discrepancy may be explained by the inference that Tavernier never actually examined the stone, but he only described it from accounts given by others. This deduction, together with new evidence showing that the stone actually weighed ~193.5 ct, indicates a high likelihood that the Great Mughal is the same as the Orlov diamond.

The Journal of Gemmology, 35(1), 2016, pp. 56–63, http://dx.doi.org/10.15506/JoG.2016.35.1.56 © 2016 The Gemmological Association of Great Britain

Introduction Background In the work of Jean-Baptiste Tavernier (1605– One of the most frequently cited historical 1689), French diamantaire and traveller to India European travel writers is Jean-Baptiste Tavernier. and other exotic locales (Figure 1), there is a This privately active gem merchant made six description of one of the largest diamonds in journeys to the East during the period 1630–1668, the collection of the Mughal emperor Aurangzeb visiting among other countries Turkey, Persia (reigned 1658–1707)—a specimen weighing and India (e.g. Figure 2). In this last region— ~286 ct known as the Great Mughal (or Great the first known source of diamonds—Tavernier Mogul). Most who have written on the history of was most interested in just these stones, which this diamond do not question the credibility of was reflected in the work he published in 1676, Tavernier’s account (King, 1867; Jagnaux, 1885; wherein he described the methods used to mine Shipley, 1955; Bruton, 1970; Moneta Cavenago- them and problems connected with their trade. Bignami, 1980; Harlow, 1998; Balfour, 2009). The Even though the Frenchman’s reports per- Frenchman’s information regarding this stone is taining to these issues are not the only ones examined further in this article, and its possible from this period, his writings also contain an relation to the Orlov diamond is explored. account of unique value regarding the gems

56 The Journal of Gemmology, 35(1), 2016 Feature Article

Figure 2: Tavernier’s travels to the East were recorded in various manuscripts, such as this one from 1692.

Figure 1: Jean-Baptiste Tavernier is shown wearing an the diamond. He also reported that the original Oriental costume in this portrait by Nicolas de Largillière. rough stone weighed about 790 carats, and in The painting currently resides at Herzog Anton Ulrich 1656 it was given as a gift to Aurangzeb’s father Museum, Braunschweig, Germany. Emperor Shah Jahan (reigned 1628–1658; Figure 4) by Mir Jumla, previously a dignitary in the court of Aurangzeb, the ruler of the Mughal Empire at Golconda, in recognition of his support of the (Howard, 1677; Master, 1911; Moreland, 1931; de Mughals. The stone was most probably pilfered Coutre, 1991). Aurangzeb’s valuables were shown from one of the temples in Karnataka, India, by to Tavernier by the imperial gem keeper, Akel soldiers of Mir Jumla during military operations Khan. Most of these were not especially notable conducted there in 1642–1652 (Gemelli Careri, by Mughal standards, as they ‘only’ weighed from 1700). The diamond was reportedly cut by a several carats to about 60 ct. However, according Venetian, Hortensio Borgio, who worked in India to Tavernier (1692), there was one exceptional stone (as quoted in and translated by Streeter, Figure 3: Tavernier’s drawing of the Great Mughal diamond 1882, pp. 69–70; see also Balfour, 2009): appeared in his 1692 monograph. The first piece that Akel Khan placed in my hands was the great diamond, which is rose cut, round and very high on one side. On the lower edge there is a slight crack, and a little flaw in it. Its water is fine, and weighs 319½ ratis [sic], which makes 280 of our carats, the rati being ⅞ of a . Tavernier, who included a drawing of this gem in his account (Figure 3), claimed that the keeper allowed him to personally examine and weigh

Great Mughal and Orlov Diamonds 57 Feature Article

equivalent to 280 ‘of our carats’—probably is equal to ~286 metric carats (see below). The diamond described by Tavernier has not been mentioned in later sources referring to the Mughal period.

Correlations with the Orlov Diamond The stone from Tavernier’s drawing and description has been noted as being similar to the Mughal-cut Orlov diamond (Figures 5 and 6), which weighs 189.62 ct and is presently kept at the Moscow Kremlin in Russia (Rybakov, 1975; Polynina, 2012; Malecka, 2014b; Shcherbina, 2014). Several legends circulate about the origins of the Orlov diamond. The most popular of them, which can be dated to Europe in the late 18th century, states this gem was taken by a French soldier from an Indian temple in Srirangam in present-day Tamil Nadu State (Dutens, 1783). Another rumour indicated that this stone was to have been an ornament for the throne of Nadir Shah, ruler of Persia, who in 1739 plundered the Mughal treasury (Pallas, 1805; Fersman 1924–25). Figure 4: Emperor Shah Jahan is shown on a throne, flanked However, according to documents from Russian on the left by his three eldest sons—Dara Shikoh, Shah archives, during the rule of Nadir Shah (1736– Shuja and Aurangzeb—while their maternal grandfather, 1747), the Orlov was in fact the property of the Asaf Khan, stands to the right. The painting dates from the Persians (although it was not necessarily kept in Mughal Period, circa ad 1628. Source: Aga Khan Museum, Persia). We do know for certain that it was taken www.agakhanmuseum.org/collection/artifact/shah-jahan- from the Persian city of Isfahan to Amsterdam by his-three-sons-and-asaf-khan-akm124. an Armenian merchant. In Amsterdam, it was sold during the second part of the 17th century. The to Catherine II, the empress of Russia (Malecka, reported weight of the resulting stone, 319½ 2014b; Malecka, in prep.-b). rattis—indicated by Tavernier (1692) as being Both the Great Mughal and Orlov diamonds have the same type of cut. According to Balfour (2009), “the pattern of facets is not dissimilar” Figure 5: The 189.62 ct Orlov diamond is shown here in the and, even more importantly, there is a small Imperial , part of the Diamond Fund collection of the Moscow Kremlin. Photo © Elkan Wijnberg. indentation in the Orlov that corresponds to the small crack on the stone described by Tavernier. Even though the similarity of these gems was already noticed in the 19th century by European writers, they were restrained from equating the stones by the information on the weight of the Great Mughal diamond as given by Tavernier. Some writers justified the differences in weight by pointing out Tavernier’s probable mistake when weighing Aurangzeb’s stone, or that this specimen decreased in size (i.e. through recutting) at a later time (Anonymous, 1853; Schrauf, 1869; Ball, 1889; Fersman, 1922; Fersman 1924–25).

58 The Journal of Gemmology, 35(1), 2016 Feature Article

However, Aziz (1942) reported that some Mughal local (Florentine) units, as he did sometimes in the authors pointed to a different weight for this stone case of gems that he saw or heard about during than that given by Tavernier (see page 60). He his Eastern voyages (see below; Tavernier, 1692). did not correlate the identity of this gem with the The present author did not, however, find any Orlov diamond, perhaps because the weight of information suggesting that the Florentine carat the Orlov was usually given by older authorities was used universally by Western gem traders at that as 185 Amsterdam or Russian carats, whereas time. Therefore, one may wonder if this conversion Aziz described it as weighing 194.75 ct, similar to was applied by Tavernier consistently in reference that given by some 19th century Russian sources to the various gems mentioned by him. In this (Anonymous, 1866; Aziz, 1942; Kuznetsova, 2009; author’s view, it is more probable that in writing Zimin and Sokolov, 2013). Figure 6: Various views of the Orlov diamond are shown Present Research in this 1767 drawing that was made in Amsterdam by Frans de Bakker. If the Orlov was in fact the same as the Previous writers pondering the correlation between Great Mughal diamond, then the image of the rough stone the Great Mughal and Orlov diamonds did not in the upper left must have been conjectural, since the analyse court texts from the Mughal Empire in diamond was previously cut in the 17th century. Source: the Persian language or sources available in the Rijksmuseum, Amsterdam, The Netherlands, www. Russian language. The present author’s research rijksmuseum.nl/nl/collectie/RP-P-1911-2912. has been largely based on such material. A matter of key significance is to determine the Western weight conversions that Tavernier used for the Indian units of the Great Mughal— rattis, also known as surkhs (Halhed, 1776). Weight units for gems (as weights and measures in general) were quite varied in Asia, Africa and Europe depending on the epoch and geographical location. Normally, the Eastern authors did not specify the local units for the weights of gems they were describing. The weight of identically named units could also differ in reference to gems vs. metals (Lockyer, 1711; Kelly, 1832; Hinz, 1955). When describing Aurangzeb’s diamond, Tavernier’s weight conversion was that 1 ratti corresponded to 0.875 of ‘our carats’ (Tavernier, 1692). Valentine Ball (1889) maintained that the Frenchman converted Eastern weight units for gems into Florentine carats, which were equivalent to about 0.196 g. Ball based his argument on information contained in Tavernier’s work pertaining to a diamond weighing 139.5 Florentine carats—the largest diamond in Europe at that time—seen by him in the collection of the Great Prince of Tuscany and known later as the Florentine diamond. The weight of this stone, cited by Tavernier and lost since the times of World War I, was very close to the 137.27 metric carats of The Great Diamond of Tuscany, as it is known from later sources (Ball, 1889; Balfour, 2009). In fact, it is probable that the weight of the Florentine diamond was reported by Tavernier in

Great Mughal and Orlov Diamonds 59 Feature Article

‘our carats’—similarly as for French livres, which he were, for example, gems of the ruler of Bijapur described as ‘our money’—the famous diamantaire and the Shah of Persia; he most probably gained had in mind the French carat commonly used in the information about these during his travels his home country, the weight of which was about from royal gem keepers or merchants.2 It is also 0.205 g (Tavernier, 1692). In that case, 1 ratti would probable that he obtained knowledge about one correspond to about 0.179 g or about 0.896 metric of the most famous diamonds of the Muslim carats, and the 319.5 rattis reported for the Great world—the Great Table, from which were cut the Mughal Diamond would thus correspond to ~286 ct. Nur al-Ayn and Darya-ye Nur stones now found in However, according to 17th century Mughal the treasury of Iran—not by analysing the original and Deccani chronicles, and most importantly a gem, as he claims, but by examining a model of letter from Shah Jahan (the owner of the stone) the stone (Malecka, 2014a; Malecka, in prep.-a). to the king of Golconda, the weight of the Great The possibility that Tavernier gained Mughal diamond was 9 tanks, which some of information about the Great Mughal diamond these sources indicate is equivalent to 216 rattis or from third parties is supported by his drawing surkhs (e.g. Mīr ’A¯lam, ah1 1266; Kha¯fī Kha¯n, 1869; of this stone (again, see Figure 3), which was Kanbūh and Yazdani, 1939; Aziz, 1942; Sarkar, described by one 19th century scholar as ‘rough’ 1951; Awrangha¯ba¯di et al., 1999), rather than the or ‘rude’ (Maskelyne, 1860a,b). His drawing 319.5 rattis reported by Tavernier. A weight of 216 could easily have been made on the basis of rattis corresponds to ~193.5 ct, if the metric carat a description, and therefore not all the details conversion suggested above is used. Again, the depicted in it should be assumed credible.3 current weight of the Orlov diamond is 189.62 ct. Indirect knowledge may account for the fact that depictions of other historical diamonds may Tavernier and the differ significantly from one another (I’tima¯d al- Salt∙anah, ah 1349; Tavakkuli Bazza¯z, ah 1380; Great Mughal Diamond Diba et al., 1998; Raby, 1999). If in fact the Great Mughal was actually somewhat If indeed Tavernier obtained information over 190 ct, why did Tavernier overstate the weight? indirectly about the Great Mughal diamond, this For this we are left with conjectures. To the best of certainly does not preclude that the presentation of this author’s knowledge, there are three possible Aurangzeb’s jewels, which he mentioned, actually explanations: (1) a mistake in estimating its weight, took place. The showing of valuables from the (2) purposeful deceit or (3) his knowledge of the treasury was often practised in the Muslim world diamond was gained indirectly, for example, on (al-Tan , ah 1393). It should be underscored, the basis of accounts given by others. ūkhi The possibility that Tavernier made a mistake however, that during Tavernier’s visit, the most in estimating the weight of the diamond by nearly valuable jewels of the Mughal court were not in 90 ct seems impossible for such an experienced the possession of Aurangzeb, but rather were kept diamantaire (Paxton, 1856). Therefore one might by his jailed father Shah Jahan, who refused to give consider that Tavernier deliberately overstated them up despite requests from his son (Manucci, the weight of the diamond, perhaps intending 1907; Begley and Desai, 1990). As a connoisseur to evoke a stronger impression on those readers of gems, Shah Jahan most certainly was attached who were told since the 16th century about the to his collection of precious objects. It should be fabulous riches of the Mughal Empire (Foster, emphasized as well that in the Islamic world, the 1921; Keene and Kaoukji, 2001). However, this author feels that the most probable explanation is 2 Another potential source of Tavernier’s information—court that Tavernier possessed only indirect knowledge inventories—should be excluded, in this author’s opinion. of the Great Mughal diamond. It is known that First, there is no evidence that the Frenchman had any the Frenchman did in fact include in his work access to them. Second, a survey of equivalent surviving material from the Islamic world shows that the weight and/ drawings and detailed descriptions of gems that or drawings of even large stones was never or rarely noted he did not examine personally. Among this group (Topkapı Sarayı Müzesi Arşivi, ah 1091). 3 It has also been suggested that the drawings contained in 1 In reporting the year of ancient scripts, ‘ah’ means Anno Tavernier’s work of the stones he most certainly saw and Hegirae, or ‘in the year of the Hijra’. handled may not be fully credible (Sucher, 2009).

60 The Journal of Gemmology, 35(1), 2016 Feature Article

involuntary transfer of valuable stones to another in prep.-b). Most likely, this same source also ruler indicated the giver’s subservient status; provided Tavernier with information pertaining to this was particularly the case for diamonds in the polished stone’s appearance. Mughal India, as their possession was an imperial monopoly (Ferishta, 1829; de Coutre, 1991; Boym, Conclusions 2009; Malecka, in prep.-b). According to Persian-language sources from the It is well worth adding that the most important epoch, in 1656 the Great Mughal diamond weighed gems, functioning as , were often worn by about 193.5 ct. This is quite close to the 189.62 ct the rulers personally. It is also known that Shah of the Orlov diamond at the Kremlin. The weight Jahan would display a diamond given to him by difference of ~3.8 ct is very small compared to the Mir Jumla by placing it on his turban (Valentijn, sizes of these stones. In fact, various sources from 1726; Malecka, in prep.-b). This author finds the Great Mughal’s time period and cultural circle it doubtful that Shah Jahan would have given have indicated that the weight of an important a stone of this importance to his son prior to gem could differ by more than a dozen carats being incarcerated. Such an event would have (Saˉravī Fath∙ Allaˉh, ah 1371; Saˉluˉr et al., ah 1374; Ridaˉ’ Qul Khaˉn Hidaˉyat, ah 1380; Fasaˉ Husain undoubtedly been noted by court chroniclers ∙ ī ’ī ∙ ī and Fasaˉ ī Rastgaˉr, 1988). In this author’s opinion, scrupulously registering movements of large ’ due to similarities in weight, shape, type of cut gems. In view of the above considerations, this and flaws, the stone given in 1656 by Mir Jumla to author suspects, as did some 19th–20th century Shah Jahan was in fact the same as the diamond authorities, that during Tavernier’s visit to the presently known as the Orlov. Since it must have Mughal court, the Great Mughal diamond in fact been presented to Shah Jahan in polished form, was in the possession of Shah Jahan, and this the abovementioned account by Tavernier about excluded the possibility of it being examined by it being cut by Hortensio Borgio cannot be true. the Frenchman (Maskelyne, 1860a; Aziz, 1942). This article provides strong evidence that Due to large discrepancies regarding the weight Tavernier did not see the diamond he described, of the diamond from Persian-language sources since during his visit at the Mughal court the stone of the epoch as compared to Tavernier’s work, most probably was in the possession of Shah the present author deduces that Tavernier did Jahan. The scene of examination of this stone was not actually see the Great Mughal diamond. The then contrived by the Frenchman in order to make presumed weight of the Great Mughal, however, the text more attractive and was incorporated into both before (~790 ct) and after fashioning (~286 the chapter containing descriptions of Aurangzeb’s valuables shown to him. ct), probably was not invented by the Frenchman himself.4 Tavernier reported the mass of imperial gems by using various units popular in India, References which he recalculated into carats only in the case Anonymous, 1853. History of the diamond. The of the diamond in question. It may therefore be Eclectic Magazine of Foreign Literature, Science, supposed that the presumed weights of the Great and Art, January, 12–13. Anonymous, 1866. O bolshom imperatorskom Mughal both prior to and after polishing were almaze. Russkiy Arkhiv, Vypusk 4 [see p. 644]. obtained from the imperial treasure keeper, who Awranga¯ ba¯ di S.K., Sha¯ hnava¯ z ʻA.a-H.i. and Prashad B., could have demonstrated the tendency—not at all 1999. The Maāthir-ul-Umarā: Being Biographies alien to his profession—to overstate the weight of the Muhammādan and Hindu Officers of the of gems possessed by his master (Brydges Jones, Timurid Sovereigns of India from 1500 to about 1833; Meen and Tushingham, 1968; Malecka, 1780 A.D., Vol. 2. Low Price Publications, Delhi, India [see p. 191]. Aziz A., 1942. The Imperial Treasury of the Indian 4 According to eminent Russian mineralogist Alexander Mughuls. Idarah-i-Adabiyāt-i-Delli, Delhi, India Fersman, one of the few experts who has studied the Orlov, [see pp. 190, 220, 242]. this stone was cut probably from a rough stone weighing ~400 ct (Fersman, 1955). Assuming that the Great Mughal Balfour I., 2009. Famous Diamonds, 5th edn. Antique diamond is identical to the Orlov, this provides an additional Collectors’ Club, Woodbridge, Suffolk, 335 pp. argument for negating Tavernier’s statement that the rough http://dx.doi.org/ 10.1108/09504121011012094, stone from which the Great Mughal was cut weighed ~790 ct. [see pp. 112, 118, 211].

Great Mughal and Orlov Diamonds 61 Feature Article

Ball V., 1889. Appendix I: i. The Great Mogul’s https://archive.org/details/codeofgentoolaws00 diamond and the true history of the Koh-i-Nur. In halh [see p. 11]. J.-B. Tavernier, Travels in India, Vol. 2, Cambridge Harlow G.E., 1998. The Nature of Diamonds. University Press, Cambridge, 2012, 431–449, http:// Cambridge University Press in association with the dx.doi.org/10.1017/CBO9781139192125. American Museum of Natural History, Cambridge Begley W.E. and Desai Z.A., 1990. The Shah Jahan and New York, New York, USA, 278 pp. [see p. Nama of ‘Inayat Khan: An Abridged History of 110]. the Mughal Emperor Shah Jahan (...). Oxford Hinz W., 1955. Islamische Masse und Gewichte; University Press, Delhi, India, 624 pp. [see p. Umgerechnet ins metrische System. E.J. Brill, Lei- 564]. den, The Netherlands, 66 pp. Boym M., 2009. Michała Boyma Opisanie Świata. Ed. Howard H., 1677. A description of the diamond- and transl. by E. Kajdański, Oficyna Wydawnicza mines, as it was presented by the Right Volumen, Warsaw, Poland, 325 pp. [see pp. 299– Honourable, the Earl Marshal of England, to 300]. the Royal Society. Philosophical Transactions Bruton E., 1970. Diamonds. N.A.G. Press, London, of the Royal Society, 12, 907–917, http://dx.doi. 372 pp. [see Fig. 10.1, p. 160]. org/10.1098/rstl.1677.0028. Brydges Jones H., 1833. The Dynasty of the Kajars. J. I’tima¯ d al-Saltanah, ah 1349. Sadr al-tawa¯ rīkh: Sharh-i Bohn, London [see p. cxxxviii]. ∙ h∙a¯ l-i ∙sadr a’z∙ amha¯ -i pa¯ dsha¯ ha¯ n-i qa¯ ja¯ r; az Ha¯ jj de Coutre J., 1991. Andanzas Asiáticas. Ed. by E. Ibra¯ hīm Kala¯ ntar ta Mīrza¯ ‘Alī Asgar Kha¯ n Amīn Stols, B. Teensma and J. Verberckmoes, Historia ∙ as-Sult∙ a¯ n. Ed. by M. H∙. Kha¯ n, Wah∙īd, Tihra¯ n [see 16, Madrid, Spain, 494 pp. [see pp. 254–267]. p. 91]. Diba L., Ekhtiar M. and Robinson B.W., Eds., 1998. Jagnaux R., 1885. Traité de Minéralogie Appliquée Royal Persian Paintings: The Qajar Epoch 1785– aux Arts, a l’Industrie, au Commerce et a 1925. Brooklyn Museum of Art in association l’Agriculture. Octave Doin, Paris, France, 883 pp. with I.B. Tauris Publishers, Brooklyn, New York, [see p. 171]. USA, 296 pp. [see nos. 40, 76]. Kanbuˉh M.S. and Yazdani G. 1939. ‘Amal-i Sa¯ lih : al- Dutens L., 1783. Des Pierres Précieuses et des Pierres ∙ ∙ mawsuˉ m bih Sha¯ hʹjaha¯ nʹna¯ mah, Vol. 3. Asiatic Fines avec les Moyens de les Connaître & de les Society, Calcutta, India [see p. 235]. Évaluer. Joseph Molini, , Italy, 151 pp. Keene M. and Kaoukji S., 2001. Treasury of the World: [see p. 33]. Jewelled Arts of India in the Age of the Mughals. Fasa¯ ’ī Husainī H. and Fasa¯ ’ī Rastga¯ r M., 1988. ∙ ∙ Thames & Hudson in association with the al- Fa¯ rsna¯ mah-‘i Na¯ sirī, Vol. 1. Mu’assasah-i ∙ Sabah Collection, Dar al-Athar al-Islamiyyah and Intisha¯ ra¯ t-i Amir Kabir, Tehran, Iran, 866 pp. [see p. 659]. Kuwait National Museum, London, 160 pp. [see Ferishta M.K., 1829. History of the Rise of the p. 6]. Kelly P., 1832. Oriental Metrology; Comprising the Mahomedan Power in India, till the Year ad 1612, Vol. 3. Transl. by J. Briggs, Cambridge University Monies, Weights, and Measures of the East Indies, Press, Cambridge, 2013, 544 pp., http://dx.doi. and other Trading Places in Asia, Reduced to org/10.1017/CBO9781139506670 [see p. 84]. the English Standard by Verified Operations. Fersman A., 1922. Almaz Shah. Izvestiya Rossiiskoi Longman, Rees, Orme, & Co., London, 178 pp. Akademii Nauk, Seriia 6, 16(1–18), 451–462. [see pp. 30, 36, 48, 91]. Fersman A., 1924–25. Almaznyi Fond SSSR. Narodnoy Kha¯ fi Kha¯ n M.H., 1869. The Muntakhab al-luba¯ b of Kommissariat Finansov, Moscow, Russia, Vypusk Kha¯ fī Kha¯ n, Part 1. Ed. by Ahmad Kabir al-Din, IV [see pp. 10–11]. College Press, Calcutta, India [see p. 753]. Fersman A., 1955. Kristallografiia Almaza. Izd-vo King C.W., 1867. The Natural History, Ancient and Akademii Nauk SSSR, Moscow, Russia, 566 pp. Modern, of Precious Stones and Gems, and of (republished in 2013 by Book on Demand Ltd.) Precious Metals, Vol. 1. Bell & Daldy, London [see [see p. 482]. pp. 82–83]. Foster W., 1921. Early Travels in India, 1583–1619. Kuznetsova L.K., 2009. Peterburgskie Iuveliry: Vek S. Chand, Delhi, India, https://archive.org/details/ Vosemnadtsatyĭ, Brilliantovyĭ. Tsentrpoligraf, earlytravelsinin00fostuoft [see pp. 101–102, Moscow, Russia, 542 pp. [see p. 174]. 112]. Lockyer C., 1711. An Account of the Trade in India Gemelli Careri G.F., 1700. Giro del Mondo del Dottor (…). Samuel Crouch, London, 352 pp. [see p. D. Gio. Francesco Gemelli Careri, Vol. 3. Giuseppe 263]. Roselli, Naples, Italy, https://archive.org/details/ Malecka A., 2014a. The mystery of the Nur al-‘Ayn girodelmondodeld03geme [see pp. 264-265]. diamond. Gems&Jewellery, 23(7), 20–22. Halhed N.B., 1776. A Code of Gentoo Laws, or, Malecka A., 2014b. Did Orlov buy the Orlov? Ordinations of the Pundits (...), London, 396 pp., Gems&Jewellery, 23(6), 10–12.

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Malecka A., in prep.-a. Was the Great Table a Safavid Sarkar J.N., 1951. The Life of Mir Jumla, the General of stone? On the origin of the most important crown Aurangzab. Thacker, Spink, Calcutta, India, 362 jewel of Iran. pp. [see p. 106]. Malecka A., in prep.-b. Amulets, Poisons and Royal Schrauf A., 1869. Handbuch der Edelsteinkunde. Splendor: Diamonds in the Islamic World, Part II: Druck und Verlag von C. Gerold’s Sohn, , Diamond Biographies. Austria, 252 pp. [see pp. 103–104]. Manucci N., 1907. Storia do Mogor: Or Mogul India, Shcherbina E., 2014. Indiia: Dragotsennosti, Pokorivs- 1653–1708, Vol. II. Ed. and transl. by W. Irvine, hie Mir. Gosudarstvennye Muzei Moskovskogo John Murray, London, 482 pp. [see p. 20]. Kremlia, Moscow, Russia, 427 pp. [see p. 15]. Maskelyne N.S., 1860a. On diamonds. The Chemical Shipley R.M., 1955. Famous Diamonds of the World. News, 1, 208–213. Gemological Institute of America, Los Angeles, Maskelyne N.S., 1860b. On diamonds. The Engineer, California, USA, 62 pp. [see pp. 13–15]. 9, 25 May, 329. Streeter E.W., 1882. The Great Diamonds of the Master S., 1911. The Diaries of Streynsham Master, World. Their History and Romance. Ed. by J. 1675–1680, and Other Contemporary Papers Hatton and A.H. Keane, George Bell & Sons, Relating Thereto. Ed. by R.C. Temple, John Murray, London, 346 pp., https://archive.org/details/ London, 512 pp., https://archive.org/details/ greatdiamondsofw00stre [see p. 69]. diaries16751680o02mastuoft [see pp. 172–174]. Sucher S., 2009. A crystallographic analysis of Meen V.B. and Tushingham A.D., 1968. Crown Jewels the Tavernier . Gems & Gemol- of Iran. University of Toronto Press, Toronto, ogy, 45(3), 178–185, http://dx.doi.org/10.5741/ Canada, 159 pp. [see p. 53.]. gems.45.3.178. Mir ʼA∙ lam, Abuˉ al-Qa¯ sim, ah 1266. H∙ adīqat al-‘a¯ lam, al-Tanuˉkhī, Muh∙sin ibn ‘Ali, ah 1393. Mukhta∙sar Vol. 1. Hyderabad, India [see, p. 357]. Nishwa¯ r al-muh∙ a¯ d∙ arah wa-akhba¯ r al-mudha¯ - Moneta Cavenago-Bignami S., 1980. Gemmologia. karah, Vol. 8. Da¯ r S∙ a¯ dr, Beirut, Lebanon [see pp. Hoepli, Milan, Italy, 1,734 pp. [see pp. 282– 243–245]. 283]. Tavakkuli Bazza¯ z M., ah 1380. Gawhar-i Īra¯ n. Moreland W.A., 1931. Relations of Golconda in the Muʼassasah-i Farhangi Hunari-i Aˉ ryan, Tihrān, Early Seventeenth Century. Hakluyt Society, 159 pp. [see p. 118]. London, 109 pp. [see pp. 31–33]. Tavernier J.-B., 1676. Les Six Voyages de Jean Baptiste Pallas (P.S.), 1805. Istoricheskoie izvestie o bolshom Tavernier (…) en Turquie, en Perse, et aux Indes almaze, nakhodiashchemsa nynie v rossiisko- (…). Paris, France, 604 pp. imperatorskom skipetre. Vestnik Evropy, 12, June Tavernier J.-B., 1692. Les Six Voyages de Jean Baptiste [see p. 291]. Tavernier (…) en Turquie, en Perse, et aux Indes Paxton J.R., 1856. Jewelry and the Precious Stones: (…), Vol. 2. Paris, France, 782 pp. [see pp. 278– With a History, and Description from Models, 279, 294, 549]. of the Largest Individual Diamonds Known: Topkapı Sarayı Müzesi Arşivi, ah 1091. Manuscript Including, Particularly, a Consideration of the D. 12/1–2. Koh-i-Noor’s Claim to Notoriety. John Penington Valentijn F., 1726. Oud en nieuw Oost-Indiën (…), & Son, Philadelphia, USA, 40 pp., https://archive. Vol. 4, Part 2. Joannes van Braam, Dordrecht, The org/details/jewelrypreciouss00paxt [see p. 20]. Netherlands, 151 pp. Polynina I., 2012. Sokrovishcha Almaznogo Fonda Zimin I.V. and Sokolov A.R., 2013. Iuvelirnye Rossii. Slovo, Moscow, Russia [see p. 190]. Sokrovishcha Rossiiskogo Imperatorskogo Dvora Raby J., 1999. Qajar Portraits. Azimuth Editions in [The Jewelry Treasure of the Russian Imperial association with the Iran Heritage Foundation, Court]. Tsentrpoligraf, Moscow, Russia, 766 pp. London, 104 pp. [see no. 110]. [see table 25]. ah 1380. Ta¯ r kh-i rawdat as- Rid∙ a¯ ’ Qulī Kha¯ n Hida¯ yat, i ∙ ∙ safa¯ fi sirat al-anbiya¯ ’ wa al-muluˉk wa al hulafa¯ ʼ, ∙ ˘ The Author Vol. XIII. As∙a¯ ∙tir, Tihra¯ n [see p. 7,098]. Rybakov B.A., 1975. Sokrovishcha Almaznogo Fonda Anna Malecka SSSR [Treasures of the USSR Diamond Fund]. Kalima Project, Abu Dhabi Authority for Culture Izobrazitelnoe Iskusstvo, Moscow, Russia [see and Heritage, United Arab Emirates Skipetr Imperatorskii entry]. Email: [email protected] Sa¯ luˉr Q.M., Sīsta¯ nī Iˉ.A., Afsha¯ r Ī. and Sa¯ lūr M., ah 1374. Ruˉzna¯ mah-ʼi kha¯ ∙tira¯ t-i ʻAyn al-Salt∙ anah, Acknowledgement Vol. 2. Asa¯ ∙tīr, Tihra¯ n [see p. 1,014]. The author wishes to thank three anonymous Sa¯ ravī Fath∙ Alla¯ h M., ah 1371. Ta¯ rikh-i Muh∙ ammadi: reviewers for their useful comments and Ah∙ san al-Tava¯ rikh. Muʼassasah-i Intisha¯ ra¯ t-i Amir assistance in the preparation of this paper. Kabir, Tehran, 403 pp. [see p. 255].

Great Mughal and Orlov Diamonds 63 Gemmological Brief

A Lead-Glass-Filled Corundum Doublet

Supparat Promwongnan, Thanong Leelawatanasuk and Saengthip Saengbuangamlam

In September 2015, a 1.75 ct pink sapphire was submitted to the Gem and Jewelry Institute of Thailand’s Gem Testing Laboratory (GIT-GTL). The stone showed internal features (e.g. flash effects and trapped gas bubbles) that are commonly seen in lead-glass-filled rubies and sapphires. In addition, the sample turned out to be an assembled stone, consisting of a pink sapphire crown and a near-colourless sapphire pavilion. These two portions were joined along a lead-glass-filled contact layer slightly below the girdle that locally contained areas of corundum fragments. We concluded that this stone was a lead-glass-filled corundum doublet.

The Journal of Gemmology, 35(1), 2016, pp. 64–68, http://dx.doi.org/10.15506/JoG.2016.35.1.64 © 2016 The Gemmological Association of Great Britain

Introduction a gemmological microscope and an immersion Lead-glass-filled corundum was first encountered microscope using methylene iodide. In addition, over a decade ago, and has continued to appear the gem was viewed with a DiamondView in the gem market in various forms (see, e.g., instrument. We used a Thermo Nicolet 6700 Kitawaki, 2004; Smith et al., 2005; McClure et al., Fourier-transform infrared (FTIR) spectrometer 2006; Milisenda et al., 2006; SSEF, 2009; Henn et Figure 1: This 1.75 ct pear-shaped stone proved to consist of al., 2014, Leelawatanasuk et al., 2015; Ounorn and a sapphire doublet containing fissures and cavities filled with Leelawatanasuk, 2015; Panjikar, 2015). Nowadays lead glass. Photo by S. Saengbuangamlam. such treated stones are widely available, mostly in the low-end jewellery market. The starting material typically consists of low-quality corundum, although a variety of colours and transparencies have been treated by this method (see references above). In September 2015, the GIT-GTL received an unusual lead-glass-filled sapphire that was characterized for this report.

Sample and Methods The 1.75 ct sample consisted of a pear-shaped modified brilliant measuring 8.32 × 7.21 × 3.81 mm (Figure 1). We used standard gemmological instruments to measure the stone’s properties, and its internal features were observed with both

64 The Journal of Gemmology, 35(1), 2016 Gemmological Brief

Contact layer Corundum fragments

Figure 2: The doublet consists of a pink sapphire crown and a near-colourless sapphire pavilion that are joined along a contact layer located slightly below the girdle (left, image width 6.5 mm). Viewed with higher magnification, the contact layer is seen to locally consist of dark (isotropic) glassy material containing some anisotropic angular fragments of corundum (right, image width 2.2 mm). Photomicrographs by S. Promwongnan, in immersion with cross-polarized light. to obtain IR transmittance spectra in the range of Further examination with a standard gem- 4000–400 cm−1. X-radiography was performed with mological microscope at high magnification a Softex SFX-100 instrument. Chemical analysis was showed internal features indicative of lead- carried out by energy-dispersive X-ray fluorescence glass-filled corundum. A blue flash effect as- (EDXRF) spectroscopy using an Eagle III system. sociated with filled fractures/fissures was the most prominent characteristic, and was seen Results in both the pink and near-colourless portions (Figure 3a). Several trapped gas bubbles also Basic Properties were clearly seen in the filled fissures (Figure The gemmological properties of this stone were 3b). Additional inclusions consisted of minute consistent with natural corundum. It had RIs of particulates (Figure 3c) and planar ‘fingerprints’ 1.770–1.761 (measured on the table facet) and a (Figure 3d), which suggested that the corundum hydrostatic SG of 3.98. The polariscope gave a pieces forming both parts of this stone were of doubly refractive, uniaxial negative reaction. The natural origin. stone fluoresced moderate red to long-wave UV In the DiamondView, the relatively low lustre radiation, with somewhat weaker luminescence of the glass-filled cavities could be seen easily to short-wave UV. with reflected light using the instrument’s sample chamber illuminator (Figure 4a). When exposed Microscopic Features to the DiamondView’s deep-UV excitation, the When the sample was examined using an glassy material was inert and appeared as dark immersion microscope between crossed polar- areas along the contact layer and in fissures and izers, it was obvious that it was actually a cavities, in contrast to the strong red fluorescence composite stone (Figure 2, left). It consisted of the host corundum (Figure 4b,c). In places, the of a doublet formed of two distinctly different contact layer contained some bright-luminescing pieces: pink sapphire for the crown and near- angular fragments of corundum embedded in the colourless sapphire for the pavilion. These two dark-appearing glassy material. pieces were joined together along a contact layer located slightly below the stone’s girdle. Higher Mid-Infrared Spectroscopy magnification (Figure 2, right) revealed that the The mid-IR spectrum of the sample showed contact layer was filled with glassy material that broad absorption features at approximately 3500, locally contained randomly oriented fragments of 2597 and 2256 cm−1 that are commonly present in corundum. lead-glass-filled corundum (Figure 5).

Lead-Glass-Filled Corundum Doublet 65 Gemmological Brief

a b

c d

Figure 3: Internal features seen in the lead-glass-filled corundum doublet consist of (a) several filled fractures showing blue flash effects, (b) gas bubbles trapped inside the filler, (c) minute particulates and (d) planar fingerprints. Photomicrographs by S. Promwongnan; image widths 2.1, 1.5, 1.6 and 1.1 mm for photos a–d, respectively.

X-radiography many fractures inside the host corundum and in The X-ray image of the stone (Figure 6, left) cavities on the stone’s surface. These results are revealed that the contact layer consisted of a high- consistent with the presence of a lead-containing density (dark-appearing) material. Furthermore, glass filler in fissures and cavities, as well as with- high-density material also was present along in the contact layer of this doublet.

Figure 4: These DiamondView images of the 1.75 ct lead-glass-filled corundum doublet show the sample in reflected light from the sample chamber illuminator (a), and exposed to ultra-short-wave UV radiation (b and c). The glass filler has a low lustre in reflected light, and is inert to UV radiation—in contrast to the strong red fluorescence of the host corundum. Note also the presence of some angular fragments of corundum in the glassy material along the contact layer between the crown and pavilion (particularly in image c). Photos by S. Promwongnan.

a b c

Corundum fragments Filled cavities

Glassy material

66 The Journal of Gemmology, 35(1), 2016 Gemmological Brief

Table I: Trace-element contents by EDXRF of the IR Spectra corundum doublet.

Lead-glass-filled ruby Area TiO2 V2O5 Cr2O3 Fe2O3 Ga2O3 SiO2 PbO2 Studied sample Crown 0.03 0.02 0.57 0.19 0.01 0.36 0.39 Pavilion 0.02 0.02 0.11 0.19 nd* 1.63 7.11 * Abbreviation: nd = not detected.

3500

% Transmittance % Transmittance in the crown, apparently due to a larger amount 2256 2597 of glass filling encountered by the beam in that area (i.e. within fractures and/or in the contact layer of the doublet).

4000 3500 3000 2500 2000 1500 1000 500 Wavenumber (cm−1)

Figure 5: FTIR transmittance spectra are shown here for the Discussion and Conclusions tested corundum doublet as compared with a lead-glass- Based on the above evidence, it is clear that this filled ruby reference sample. Both spectra display similar stone was a lead-glass-filled doublet composed -1 broad bands at approximately 3500, 2597 and 2256 cm of pink and near-colourless sapphire. The that are commonly seen in lead-glass filled materials. The presence of small, angular corundum fragments bands at approximately 3000–2900 cm-1 in the doublet may be due to sample contamination (finger oils, etc.). within the glass-filled contact layer suggests that these two pieces could have been accidentally Chemical Analysis or intentionally brought together during the lead- EDXRF spectroscopy of the crown and pavilion glass treatment process. Bonding together of their sides of the corundum doublet showed traces flat surfaces enabled this composite material to of Ti, V, Cr, and Fe (and Ga in the crown); as be cut into an attractive but deceiving gemstone. expected, the Cr content of the pink sapphire Thus, this sample should be referred to as a lead- forming the crown side was much higher than glass-filled corundum doublet. that of the near-colourless pavilion (Table I). Also detected were significant amounts of Pb and Si in References both portions of the stone, which confirmed that Henn U., Schollenbruch K. and Koch S., 2014. Gem it was lead-glass filled. Much greater quantities of Notes: Corundum with colored lead-glass fillings. these elements were detected in the pavilion than Journal of Gemmology, 34(2), 111–112.

Figure 6: An X-ray image (left) of the lead-glass-filled corundum doublet is shown with a corresponding view taken in immersion with cross-polarized light (right). The X-rays reveal a high-density material that appears as dark areas in fractures and fissures, and along the contact layer between the crown and pavilion. Photos by S. Promwongnan; image width 6.4 mm.

Lead-Glass-Filled Corundum Doublet 67 Gemmological Brief

Kitawaki H., 2004. Lead-glass impregnated ruby. Gemmology, 45(416), May, 18 (in Japanese with English translation). Leelawatanasuk T., Susawee S., Promwongnan S. and Atsawatanapirom N., 2015. Green lead-glass-filled sapphires. Journal of Gemmology, 34(5), 420–427, http://dx.doi.org/10.15506/jog.2015.34.5.420. McClure S.F., Smith C.P., Wang W. and Hall M., 2006. Identification and durability of lead glass–filled rubies. Gems & Gemology, 42(1), 22–34, http:// dx.doi.org/10.5741/gems.42.1.22. Milisenda C.C., Horikawa Y., Manaka Y. and Henn U., 2006. Rubies with lead glass fracture fillings. Journal of Gemmology, 30(1–2), 37–42, http:// dx.doi.org/10.15506/jog.2006.30.1.37. Ounorn P. and Leelawatanasuk T., 2015. GIT Lab Update: Yellow lead-glass-filled sapphire. The Gem and Jewelry Institute of Thailand, Bangkok, 16 July, www.git.or.th/2014/eng/testing_center_ en/lab_notes_en/glab_en/2015/07/16/Yellow_ Lead-glass_filled_sapphire.pdf. Panjikar J., 2015. Gem Notes: Lead-glass-filled yellow sapphires. Journal of Gemmology, 34(6), 488– Fine Rubies, Sapphires and Emeralds 489. Bangkok - Geneva - Hong Kong - New York Smith C.P., McClure S.F., Wang W. and Hall M., 2005. Some characteristics of lead‐glass‐filled corundum. Jewellery News Asia, 255, November, 79–84. SSEF, 2009. How much glass is in the ruby? SSEF Fac- ette, 19, 8–9, www.ssef.ch/fileadmin/Documents/ PDF/facette16.pdf.

The Authors Supparat Promwongnan, Thanong Leelawatanasuk and Saengthip Saengbuangamlam Head Office: The Gem and Jewelry Institute of Thailand Crown Color Ltd. 4th Floor, ITF Tower, Silom Road, Bangrak 14/F, Central Building, suite 1408, 1-3 Pedder Street Bangkok 10500, Thailand Central Hong Kong SAR Email: [email protected] Tel:+852-2537-8986 New York Office: + 212-223-2363 Acknowledgements Geneva Office: +41-22-8100540 The authors thank Dr Pornsawat Wathanakul, Dr Visut Pisutha-Anond, Wilawan Atichat and Boontawee Sriprasert for their valuable Crown Color suggestions and their extensive reviews of this is a proud supporter of the article. Journal of Gemmology

68 The Journal of Gemmology, 35(1), 2016

Conferences

AGA Tucson Conference

The 2016 Accredited Gemologists Association Con- ference in Tucson, Arizona, USA, took place 3 February, with the theme ‘Where in the World?— Origin of Gem Species & More’. Attended by 132 people, the event was moderated by AGA president Stuart Robertson, and featured six speakers. Andrew Cody (Cody , Melbourne, Australia) began the conference with a presentation on the various types of opal, their attributes and where they have been mined, as well as current pricing trends for fine Australian opal. Dr Daniel Nyfeler (Gübelin Gem Lab, Lucerne, Switzerland) reviewed 10 years of using laser ablation– inductively coupled plasma–mass spectrometry (LA- ICP-MS) in his gemmological laboratory. The trace- element data provided by this technique is useful for the detection of treatments and synthetics, and also for determining a gem’s geographic origin. To obtain meaningful data, it is necessary to employ a Figure 1: Gem-A’s Claire Mitchell demonstrates the use of highly trained and knowledgeable operator, to have strong fibre-optic lighting to obtain a good spectrum of a a comprehensive collection of reference samples, transparent gemstone with a handheld spectroscope. Photo by Henry Mesa. and to use appropriate data reduction and processing procedures. Claire Mitchell (Gem-A, London) described to accurately assess the amount or effect of fracture the use of the spectroscope in gemmology. After filling because the stones are not seen by the labs reviewing the history and development of studying before treatment (and after cleaning of the fissures). absorption bands in gems and minerals, she explained His company no longer cleans emeralds unless the differences between prism and diffraction-grating they also perform the enhancement, since some spectroscopes, and gave several tips on how to unscrupulous dealers were obtaining laboratory obtain good spectra (e.g. the use of strong lighting; reports on cleaned stones and then having them see Figure 1). She then described the various treated. types and applications of advanced spectroscopic Marc Beverly (University of New Mexico, USA) instrumentation. described his experience visiting an enormous cavern Richard Hughes (Lotus Gemology, Bangkok, containing giant selenite crystals in Naica, Chihuahua Thailand) gave a presentation called ‘Forests and State, Mexico. The hot and humid conditions in the Trees—Ten Lessons in Gemology’ that conveyed cave, combined with the sharp and slippery crystals, some of his experience and research gleaned from created hazardous conditions, but the selenites were decades of working with gems. An overall principle awe-inspiring. The expedition has been documented that he emphasized was to beware when things do in a National Geographic video that is accessible at not make sense and to get more information before www..com/watch?v=0OLdSJmvcUs. making a decision. The conference was followed by the AGA Gala, Shawn O’Sullivan gave a presentation for Arthur where The Antonio C. Bonanno Award for Excellence Groom (Eternity Natural Emerald, Ridgewood, New in Gemology was presented to Dr Cigdem Lule Jersey, USA) on the clarity enhancement of emerald. (Gemworld International Inc., Glenview, Illinois, He indicated that it is difficult for gem laboratories USA). Brendan M. Laurs

70 The Journal of Gemmology, 35(1), 2016 Conferences

GILC Tucson Conference

The Gemstone Industry & Laboratory Conference the observer or viewing environment. To accurately took place on 1 February 2016 in Tucson, Arizona, calculate colour coordinates of a gem, these factors USA (Figure 2). The event was moderated by GILC must be taken into account, as well as the colour chairman Edward Boehm, and was attended by sensitivity of the human eye. approximately 80 invitees. Bruce Bridges (Bridges Tsavorite, Tucson, Ari- Dr Lore Kiefert (Gübelin Gem Lab, Lucerne, zona, USA) examined the traceability of a gem from Switzerland) gave a presentation for Dr Daniel the source to the end consumer. He gave examples Nyfeler on the radiogenic age dating of gems. The of some stones that are vertically integrated through ages of many gem deposits worldwide are well some or all stages of mining, processing, cutting and constrained, particularly for corundum and emerald. marketing, such as tsavorite from his operation in At the Gübelin Gem Lab, surface-reaching zircon Kenya, from the Green Dragon mine in inclusions in selected client stones are now being Namibia, emerald from the Belmont mine in Brazil analysed by LA-ICP-MS to determine the age of the and ruby from True North’s project in Greenland. At host sapphire or ruby (for more information, see the end of his presentation, he posed the question, “At The Journal article by K. Link, ‘Age determination of what level does traceability start?” zircon inclusions in faceted sapphires’, 34(8), 2015, These talks were followed by a general discussion 692–700). Combined with other methods, the resulting session that provided a lively debate on laboratory age information provides a useful piece of data to aid terminology for describing colour on reports. The geographic origin determination. conference concluded with a special announcement Dr James Shigley (Gemological Institute of by Ruben Bindra (president of the American Gem America, Carlsbad, California, USA) reviewed GIA’s Trade Association) that AGTA had revised its ‘Code research on the observation and measurement of of Ethics and Principles of Fair Business Practice’ to colour in gems. Faceted gemstones display a complex include mine-to-market traceability and transparency face-up appearance that is influenced by several source disclosure protocols; the International Colored factors, including the light source, faceting style, colour Gemstone Association adopted the revised code at (and colour distribution), visual effects (windowing, the ICA Board of Directors meeting on 31 January in extinction, etc.), pleochroism and reflections from Tucson. Brendan M. Laurs

Figure 2: Attendees of the GILC Conference in Tucson listen to one of the presentations. The topics at this year’s event included the age dating of gems, colour measurement and observation, and traceability from the source to the end consumer. Photo by Sherri Graves.

Jewelry Industry Summit

The first Jewelry Industry Summit for Responsible including manufacturers, designers and educators, Sourcing was held at the Institute of as well as NGOs and personnel from the U.S. Technology in New York, New York, USA, on Department of State. 10–13 March 2016. The 160 attendees represented The five primary objectives of the summit were all sectors of the industry from mining to retail, as follows:

Conferences 71 Conferences

Figure 3: Participants of the Jewelry Industry Summit joined focus groups to discuss various topics related to socially and environmentally responsible practices in the gem and jewellery industry. Photo by Peggy Jo Donahue.

1. Generate a broad-based awareness of facts North Chesterfield, Virginia, USA) on socially and related to the jewellery industry supply chain environmentally responsible precious metals refining. and responsible sourcing, and explore what Following the panel discussion, Eric Jens (ABN works and what does not. AMRO Bank, Amsterdam, The Netherlands) presented 2. Create a shared vision that ensures viability of his company’s strategy to help its clients generate the supply chain and all jewellery businesses as business opportunities. He also handed out an attractive they evolve to meet changing expectations from brochure (‘Sustainable Diamond Jewellery Guide’) industry members and the consuming public. outlining the details of their strategy. Though it was 3. Explore the possibility of generating industry- written with diamonds in mind, many of the practices wide goals that all members of the supply chain could theoretically be applied to the coloured stone can reasonably work toward. industry as well. 4. Begin to develop guiding principles that There were two presenters from outside will help any sector make progress through industries. Maria Gorsuch-Kennedy (EMC Corp., continuous improvement. Boston, Massachusetts, USA) discussed supply-chain 5. Decide if and how to implement and measure sustainability and how EMC applies its environmental the success of any plan resulting from these and conflict minerals program throughout its computer discussions. hardware product lifecycle. Margo Sfeir (Elevate Administration of the summit was coordinated by Global Ltd., New York City) described the responsible- Suzan Flamm, Cecilia Gardner and Sara Yood, all sourcing management tools that her company has of the Jewelers Vigilance Committee (New York City). developed to help private-label product companies Cheri Torres and Mike Feinson of Innovation Partners identify management practices to improve responsible International were hired to facilitate the summit, and sourcing. they kept ideas flowing by creating focus groups to Responsible-sourcing protocols were addressed by brainstorm on various topics (e.g. Figure 3) and report David Bouffard (Signet Jewelers, Akron, Ohio, USA) back to the larger group. This invited every attendee and Andrew Bone (Responsible Jewellery Council to be engaged and feel part of the discussion process. [RJC], London). Bouffard detailed Signet’s commitment Formal presentations were made by various to maintaining and improving consumer confidence companies within and outside the jewellery industry to in jewellery products by addressing the social, ethical share inspirational stories of success, as well as challenges and environmental risks facing the industry at large. He they faced along the way. The format included a panel outlined their recently launched responsible-sourcing of presenters from the jewellery industry that consisted protocol for diamonds, which was built on the United of Eric Braunwart (Columbia Gem House, Vancouver, Nations’ Guiding Principles on Business and Human Washington, USA) on small-scale and artisanal mining, Rights and the Due Diligence Guidance for Responsible Jamie McGlinchey (Melissa Joy Manning, Brooklyn, Supply Chains developed by the Organisation for New York) on socially responsible jewellery creation, Economic Co-operation and Development (OECD). Marcelo Ribeiro (Belmont, Minas Gerais, Brazil) on Bone focused on RJC’s independently audited Code socially and environmentally responsible emerald of Practices and Chain-of-Custody Certification and mining in Brazil, and Stewart Grice (Hoover & Strong, how they relate to diamonds, gold and -group

72 The Journal of Gemmology, 35(1), 2016 Conferences

metals. RJC, a not-for-profit organization, currently has development (Figure 4). Through collective small-scale over 700 stakeholders. mining groups who meet certain fair-trade protocols, Inspiring stories were presented by Anna Bario DDI helps the miners sell their rough diamonds to (Bario Neal, Philadelphia, Pennsylvania, USA) and selected buyers. DDI also provides assistance to these Eduardo Escobedo (Responsible Ecosystems Sourcing miners with housing, education and safer working Platform [RESP], Troinex, Switzerland). Bario described conditions. the rapid success her company has achieved while Lynsey Cesca Jones (VF Corp., Greensboro, focusing on handcrafted jewellery made with reclaimed North Carolina, USA) explained how her company has precious metals, fair-mined gold, ethically sourced addressed supply-chain sourcing issues. VF is a lifestyle, gemstones and low-impact environmentally conscious footwear and accessories company that owns brands practices. Escobedo explained RESP’s mission to create such as North Face, Timberland, Wrangler, Nautica and positive environmental, social and economic impacts JanSport. Jones presented real-world scenarios and by fostering change toward the sustainable use of how her company addressed these challenges through natural resources. A relative newcomer, RESP works improved responsible sourcing practices. with the cosmetics, fashion and jewellery industries; Hannah Koep-Andrieu (OECD) discussed the it recently published a report titled ‘Challenges to OECD Due Diligence Guide for Responsible Supply Advancing Environmental and Social Responsibility in Chains of Minerals from Conflict-Affected and High- the Coloured Gems Industry’ (see What’s New entry on Risk Areas. These guidelines recommend a five-step page 2 of this issue). framework for risk-based due diligence in the mineral Dorothée Gizenga (Diamond Development supply chain: (1) Establish strong company management Initiative [DDI], Ottawa, Ontario, Canada) gave a systems, (2) identify and assess risk in the supply chain, fascinating presentation on her organization’s activities (3) design and implement a strategy to respond to to transform artisanal mining into a source for sustainable identified risks, (4) carry out independent third-party audits and (5) report on supply-chain due diligence. Ideas resulting from the brainstorming sessions that Figure 4: Dorothée Gizenga spoke at the Jewelry Industry were held during the summit were posted on the walls Summit about Diamond Development Initiative’s efforts to of the two main meeting rooms. As the days progressed, transform artisanal mining into a source for sustainable devel- the ideas were refined to possible goals and initiatives. opment for small-scale miners. Photo by Peggy Jo Donahue. Attendees were then encouraged to come up with a number of action plans and select those that each wanted to support. Examples included helping miners and gem cutters in developing countries with safety education and using better equipment to avoid health- related issues, educating and conveying responsible- sourcing information to jewellery sales associates, researching consumer attitudes about responsible sourcing and sustainability, and communicating through various media the accomplishments of the industry in these areas. Finally, volunteers were solicited to steward the summit into its next steps and future meetings. Many industry leaders stepped up to join the new committee. Interested readers are encouraged to visit the summit’s website (www.jewelryindustrysummit.com/ new-page-3) to download information sheets related to the responsible sourcing of diamonds, coloured stones, and gold and precious metals, as well as a list of useful links regarding legal requirements, voluntary standards, association and company practices, and sourcing activities by other industries outside the gem and jewellery sector. Edward Boehm ([email protected]) RareSource, Chattanooga, Tennessee, USA

Conferences 73 Communicate colour with confidence

Sign up for our Coloured Stones Grading Course, in association with GemeWizard® — the leader in gem digital colour communication. At just £795, this course will provide you with a grounding in colour grading, an essential skill required for a successful career in appraisal, retail, auctioning and trading.

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Join us.

The Gemmological Association of Great Britain, 21 Ely Place, London, EC1N 6TD, UK. T: +44 (0)20 7404 3334 F: +44 (0)20 7404 8843. Registered charity no. 1109555. A company limited by guarantee and registered in England No. 1945780. Registered Office: 3rd Floor, 1-4 Argyll Street, London W1F 7LD.

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Gem-A Notices

CEO APPOINTED

Alan Hart FGA DGA has been appointed Chief Executive Officer of Gem-A. A former member of the Gem-A Council, Hart is currently Head of Earth Sciences Collections at the Natural History Museum, London. With a wealth of experience in the gem and mineral trade, Hart started his career at the Natural History Museum in 1981 as Assistant Minerals Scientific Officer, and gained a BSc in geology from Birkbeck College, University of London, in 1994. He progressed to his current position of Principle Curator of Gems and Minerals and Head of Earth Sciences Collections in 2012. Hart will assume his new position at Gem-A on 1 June 2016, and he will remain affiliated with the Museum as Associate Scientist with access to the collections.

GIFTS TO THE ASSOCIATION

The Association is most grateful to the following for their gifts for research and teaching purposes: Communicate colour Eric Braunwart, Columbia Gem House, Vancouver, Mauro Pantò, The Beauty in the Rocks, Laigueglia, Washington, USA, for five pieces of rough Savona, Italy, for faceted specimens of ceruleite hyalite (Guanajuato, Mexico), four faceted (Peru), hyalite (Hungary), agatized coprolite iolites (Wyoming, USA) and seven pieces of (Utah, USA), stichtite (), with confidence ruby in mica (Wyoming, USA). (Norway) and neptunite ( Gem mine, Tom Chatham, Chatham Created Gems, San California, USA). Francisco, California, USA, for a flux-grown Helen Serras-Herman FGA, Gem Art Center, Rio synthetic sapphire crystal containing a platinum Rico, Arizona, USA, for a slab of ‘bumble bee Sign up for our Coloured Stones Grading Course, in association with inclusion. ’ from Indonesia. GemeWizard® — the leader in gem digital colour communication. Anzor Douman, Arzawa Mineralogical Inc., Ashish Sogani, Rakhi Inc., New York, New York, Winchester, Virginia, USA, for specimens of USA, for a mother-of-pearl bead and a glass-filled At just £795, this course will provide you with a grounding in colour rough (Afghanistan), turquoise (Iran), sapphire, and faceted samples of amethyst, green demantoid (Iran), a sapphire crystal (Pakistan), crackled quartz, rock crystal (faceted bead), grading, an essential skill required for a successful career in appraisal, and rough and cut Mali garnets. tourmalinated quartz, and ‘tiger iron’ retail, auctioning and trading. Zena Haddad for a square plate of Kenyan soapstone quartz. called a ‘Kisii stone’ after the Kisii tribe that lives Dr Thet Tin Nyunt, Gemological Science Centre, in the Tabaka Hills in western Kenya; the plate Yangon, Myanmar, for two rough pieces of For more information or to sign up contact [email protected]. features a giraffe image. colourless beryl (Kuaukse, Mandalay, Myanmar). Craig Hazelton, Lafayette, Colorado, USA, for a Sid Tucker, Homedale, Idaho, USA, for pyrope gem crystal (Aquatera claim, Mt. Antero, gravel concentrated by ants (Navajo Nation, Colorado, USA). Arizona, USA). Dr Jaroslav Hyršl, Prague, Czech Republic, for a Dr Marco Campos Venuti, Seville, Spain, for a rough rough piece of (Dolní Bory, Moravia, piece of polyhedral agate (Rio Grande do Sul, Czech Republic). Brazil) and a cabochon reportedly cut from Join us. Dr Michele Macrì, , Italy, for four faceted thomsonite (Portugal). chrome diopsides (Brazil). Bear Williams FGA and Cara Williams FGA, Stone Marcus McCallum FGA, Hatton Garden, London, for Group Labs, Jefferson City, Missouri, USA, for six a copy of Gems&Jewellery, 1(4), 1992 (following simulated turquoise beads (dyed and stabilized The Gemmological Association of Great Britain, 21 Ely Place, London, EC1N 6TD, UK. T: +44 (0)20 7404 3334 F: +44 (0)20 7404 8843. a Gem-A appeal for that issue). magnesite) showing various colours and markings. Registered charity no. 1109555. A company limited by guarantee and registered in England No. 1945780. Registered Office: 3rd Floor, 1-4 Argyll Street, London W1F 7LD.

Gem-A Notices 75

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MEMBERSHIP

At a meeting of the Council held on 11 March 2016, Miranda Wells was appointed as Chair of the Gem-A Council. Wells, Head of Gemmology at Birmingham City University and Course Director of the BSc (Hons) Gemmology & Jewellery Studies degree, has been a member of the Council for four years. The Council also appointed Paul Greer DGA and Kerry Gregory FGA DGA as Vice Chairs. Wells succeeds Nigel Israel FGA DGA, who remains a member of the Council. The Council of the Association have elected the following to membership: Fellowship (FGA) Wang Siyu, Beijing, P.R. China Baptiste, Karen Anne, Panadura, Sri Lanka Chan Wai Keung, Kowloon, Hong Kong Associate Membership Davison, Alexander, Southend-on-Sea, Essex Armstong, Ceri Louise, Clapham, London Ji Kaijie, Shanghai, P.R. China Armstrong, Richard, , Texas, USA Saksirisamphan Rimml, Phornthip, Näfels, Switzerland Corkum, John, Niagara Falls, Ontario, Canada Slootweg, Peter, Nootdorp, Zuid-Holland, Golden, Scott, Houston, Texas, USA The Netherlands Hamadi, Sam, Newcastle-upon-Tyne, Tyne & Wear Kearns, Bobbi, Knoxville, Tennessee, USA Diamond Membership (DGA) Oakley, Sally, Wombourne, Staffordshire Belsham, Lesley, Great Dunmow, Essex Van Leeuwen, Suzanne, Amsterdam, The Netherlands Imre, Alexandra Terez Jenssen, Sevenoaks, Kent Wheat, Barbara, Astoria, New York, USA

OBITUARY

Leonard Baker 1921–2016

Leonard Alfred Baker FGA (D. 1948), Gemmological Association of Great of Ferndown, Dorset, passed away on Britain. 21 March 2016. At Gem-A’s centenary He then formed a manufacturing celebration in 2013, Leonard was jewellery company, Leonard A. Baker honoured with a Lifetime Membership Ltd. A facsimile of the jewelled as the longest-standing Fellow of the peacock inspired by the throne of Association. Titania’s earned his company Leonard was born in Barnsbury, recognition from the Arts Council, and North London, in March 1921. He he was awarded a Fellowship of the entered the Royal Air Force in Septem- Royal Society of Arts (FRSA). ber 1940 as a mechanic working on After 38 years of manufacturing Hampden bombers and volunteered jewellery for celebrities from around on a number of occasions to fly the world, his company gained the as aircrew (gunner), during one of distinction of a unique official Post which he was shot down on a return Office address: Messrs Leonard A. trip from Hanover, Germany. He Baker Ltd, Oxford Circus, London, was discharged from the RAF in August 1946 with an England. This was an achievement of which he was unblemished record. justly proud. He joined his father, George Baker, to be Although Leonard retired in 1984, he continued trained as a jeweller before taking a jewellery lecturing worldwide on gems and gemmology until manufacturing apprenticeship with master craftsman 1997. E. A. Wallace (formerly of English Art Works, who Leonard leaves his grandson Lee Baker (the supplied Cartier). After attending night school to author of this obituary), Lee’s wife Caroline and great- study gems, in 1948 he qualified in the Gemmology grandson Luke. He will be sadly missed by close Diploma examination and became a Fellow of the family and friends. Lee Baker

76 The Journal of Gemmology, 35(1), 2016 INSTRUMENTS

Gem-A Members and Gem-A registered students receive 5% discount on books and 10% discount on instruments from Gem-A Instruments.

Contact [email protected] or visit www.gem-a.com for a catalogue.

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Gem-A Notices 77 Learning Opportunities

CONFERENCES AND SEMINARS

ASJRA’s Weekend in Washington: Great Estates, 15th Rendez-Vous Gemmologiques de Paris Historic Jewelry, and Decorative Arts 13 June 2016 13–14 May 2016 Paris, France Washington DC, USA www.facebook.com/pages/Association-Française-de- www.jewelryconference.com/sched.html Gemmologie 30th Annual Santa Fe Symposium Scandinavian Gem Symposium 15–18 May 2016 18 June 2016 Albuquerque, New Mexico, USA Kisa, Sweden www.santafesymposium.org http://sgs.gemology.se

37th World Diamond Congress Sainte-Marie-aux-Mines 53rd Mineral & Gem Show 16–19 May 2016 23–26 June 2016 Dubai, United Arab Emirates Sainte-Marie-aux-Mines, France http://diamondcongress2016.com www.sainte-marie-mineral.com/english/modules/ 8th International Conference on Mineralogy cultural-activities and Museums Note: Includes a seminar programme. 17–19 May 2016 2nd Eugene E. Foord Symposium on Changsha, Hunan, China 15–19 July 2016 www.mm8-2016.cn Golden, Colorado, USA SNAGneXt www.colorado.edu/symposium/pegmatite 18–21 May 2016 Asheville, North Carolina, USA Northwest Jewelry Conference www.snagmetalsmith.org/events/snagnext 12–14 August 2016 Seattle, Washington, USA China (Changsha) Mineral & Gem Show www.northwestjewelryconference.com 19–23 May 2016 Changsha, China 46th ACE IT Annual Mid-Year Education www.changsha-show.com/enindex.html Conference Note: Includes a seminar programme. 13–16 August 2016 Newport Beach, California, USA 10th International Conference on New Diamond www.najaappraisers.com/html/conferences.html and Nano Carbons 22–26 May 2016 Dallas Mineral Collecting Symposium Xi’an, China 19–21 August 2016 http://ndnc2016.xjtu.edu.cn Dallas, Texas, USA JCK Talks 2016 www.dallassymposium.org 2–6 June 2016 35th International Geological Congress Las Vegas, Nevada, USA 27 August–4 September 2016 http://lasvegas.jckonline.com/Education Cape Town, South Africa Maine Workshop 2016 www.35igc.org 27 May–4 June 2016 Sessions of Interest: Gems: Bringing the World Poland, Maine, USA Together; The Dynamic Earth and Its Kimberlite, http://pegworkshop.com Cratonic Mantle and Diamond Record Through Time; Diamonds and Crustal Recycling into Deep Mantle 12th International GeoRaman Conference 9–15 June 2016 Internationrence on Diamond and Carbon Novosibirsk, Russia Materials http://georaman2016.igm.nsc.ru 4–8 September 2016 Le Corum, Montpellier, France Compiled by Georgina Brown and Brendan Laurs www.diamond-conference.elsevier.com

78 The Journal of Gemmology, 35(1), 2016 Learning Opportunities

ASA 2016 International Appraisers Conference Denver, Colorado, USA 11–14 September 2016 www.denvermineralshow.com Boca Raton, Florida, USA Note: Includes a seminar programme. www.appraisers.org/Education/conferences/ASA- Conference 42nd Pacific Northwest Chapter Friends of Mineralogy Symposium 2nd European Mineralogical Conference (emc2016) 14–16 October 2016 11–15 September 2016 Longview, Washington, USA Rimini, Italy www.friendsofmineralogy.org/symposia.html http://emc2016.socminpet.it Sessions of Interest: Gem Materials; Inclusions in Gem-A Conference Minerals as a Record of Geological Processes; New 5–8 November 2016 Analysis Methods and Application London IRV Loughborough Conference www.gem-a.com/news--events/gem-a-conference-2016.aspx 17–19 September 2016 Loughborough Gem and Jewelry Institute of Thailand www.jewelleryvaluers.org/Loughborough-Conference Conference (GIT 2016) 14–15 November 2016 49th Annual Denver Gem & Mineral Show Pattaya, Thailand 16–18 September 2016 www.git.or.th/2014/index_en.html EXHIBITS Europe Smycken: Jewellery. From Decorative to Practical Fabergé – The Tsar’s Jeweller and the Ongoing Connections to the Danish Royal Family Nordiska Museet, Stockholm, Sweden 12 May–25 September 2016 www.nordiskamuseet.se/en/utstallningar/jewellery Museet på Koldinghus, Kolding, Denmark www.koldinghus.dk/uk/exhibitions/exhibitions-2016/ North America faberge.html A Passion for Jade: The Heber Bishop Collection Open Space—Mind Maps. Positions in Until 19 June 2016 Contemporary Jewellery The Metropolitan Museum of Art, New York, New Until 15 May 2016 York, USA Nationalmuseum Design, Stockholm, Sweden www.metmuseum.org/exhibitions/listings/2015/ www.nationalmuseum.se/English-startpage/ passion-for-jade Exhibitions/Open-Space--Mind-Maps Variations on a Theme: 25 Years of Design from Take it Personally [jewellery and adornment] the AJDC Until 1 June 2016 Until July 2016 Museum of Cultural History, Oslo, Norway Gemological Institute of America, Carlsbad, www.khm.uio.no/english/visit-us/historical-museum/ California, USA temporary-exhibitions/2015/this-is-personal.html www.gia.edu/gia-museum-variations-theme-25-years- design-AJDC A Motley Crew—New Pieces from the Collection Until 12 June 2016 Thunderbirds: Jewelry of the Santo Domingo Schmuckmuseum, Pforzheim, Germany Pueblo www.schmuckmuseum.de/flash/SMP_en.html Until 5 September 2016 Abby Aldrich Rockefeller Folk Art Museum, Heavenly Bodies—The Sun, Moon and Stars in Williamsburg, Virginia, USA Jewellery http://tinyurl.com/zgyd54k 8 July–30 October 2016 Schmuckmuseum, Pforzheim, Germany Fabergé from the Matilda Geddings Gray www.schmuckmuseum.de/flash/SMP_en.html Foundation Collection Until 27 November 2016 Elements: From Actinium to Zirconium The Metropolitan Museum of Art, New York, New Until 26 February 2017 York, USA Ulster Museum, Belfast, Northern Ireland www.metmuseum.org/exhibitions/listings/2011/ http://nmni.com/um/What-s-on/Elements faberge

Learning Opportunities 79 Learning Opportunities

Glitterati: Portraits & Jewelry from Colonial Fabergé: From a Snowflake to an Iceberg Latin America Ongoing Until 27 November 2016 Houston Museum of Natural Science, Texas, USA Denver Art Museum, Denver, Colorado, USA www.hmns.org/exhibits/special-exhibitions/faberge- www.denverartmuseum.org/exhibitions/glitterati a-brilliant-vision/

Arts of Islamic Lands: Selections from The Gemstone Carvings al-Sabah Collection, Kuwait Ongoing Until 29 January 2017 Houston Museum of Natural Science, Texas, USA Museum of Fine Arts, Houston, Texas, USA www.hmns.org/exhibits/special-exhibitions/ www.mfah.org/exhibitions/arts-islamic-lands- gemstone-carvings selections-al-sabah-collection- Gilded New York American Mineral Heritage: Harvard Collection Ongoing Until February 2017 Museum of the City of New York, New York, USA Flandrau Science Center & Planetarium, Tucson, www.mcny.org/content/gilded-new-york Arizona, USA http://flandrau.org/exhibits/harvard Jewelry, from Pearls to Platinum to Plastic Ongoing Gold and the Gods: Jewels of Ancient Nubia Newark Museum, New Jersey, USA Until 14 May 2017 www.newarkmuseum.org/jewelry Museum of Fine Arts, Boston, Massachusetts, USA www.mfa.org/exhibitions/gold-and-gods Mightier than the Sword: The Allure, Beauty and Enduring Power of Beads Secrets: Feathers from the Age of Ongoing Dinosaurs Yale Peabody Museum of Natural History, Yale Ongoing University, New Haven, Connecticut, USA Houston Museum of Natural Science, Texas, USA http://peabody.yale.edu/exhibits/mightier-sword- www.hmns.org/exhibits/special-exhibitions/amber- allure-beauty-and-enduring-power-beads secrets-feathers-from-the-age-of-dinosaurs

City of Silver and Gold: From Australia Tiffany to Cartier A Fine Possession: Jewellery & Identity Ongoing Until 22 May 2016 Newark Museum, New Jersey, USA Powerhouse Museum, Sydney, New South Wales, Australia www.newarkmuseum.org/SilverAndGold.html www.powerhousemuseum.com/exhibitions/jewellery OTHER EDUCATIONAL OPPORTUNITIES

Gem-A Workshops and Courses Morogoro, Umba, Arusha, Longido, Merelani and Gem-A, London Lake Manyara, Tanzania www.gem-a.com/education/course-prices-and-dates.aspx www.free-form.ch/tanzania/gemstonesafari.html

Advanced Diamond Program Lectures with The Society of Jewellery Historians 16 or 17 May 2016 Burlington House, London, UK Birmingham www.societyofjewelleryhistorians.ac.uk/current_ www.naj.co.uk/en/news/events-conferences.cfm/ lectures seminar-for-valuers-identifying-synthetic-and-treated- 28 June 2016 diamonds Neil Wilkin— Age Bodily Adornment: How was It Made and Worn? Minerals and Gems: Unlocking the Earth's Treasure Chest 27 September 2016 21 June–9 August 2016 Galina Korneva—The Grand Duchess Maria Harvard University Summer School, Cambridge, Pavlovna’s Contacts with Paris Jewellers and Her Massachusetts, USA Collection of Treasures www.summer.harvard.edu/courses/minerals-gems- 25 October 2016 unlocking-earths-treasure-chest/33384 Robert Baines—Bogus or Real: Jewellery and the Capture of Human Drama Gemstone Safari to Tanzania 22 November 2016 11–28 July 2016 Kieran McCarthy—Fabergé and London

80 The Journal of Gemmology, 35(1), 2016

New Media

Exotic Gems, Vol. 4: How to Identify, Evaluate & Select Jade & Pearls

By Renée Newman, by Chapter 3, ‘ or Nephrite Jade?’ The latter 2016. International includes a useful table, ‘Characteristics of Jadeite Jade Jewelry Publications, Los Versus Nephrite Jade’, which compares and contrasts Angeles, California, USA, their various properties (e.g. chemical formulas, RIs, 136 pages, ISBN 978- reaction to heat, etc.) according to 19 categories. 0929975504. US$19.95 Chapters 4 and 5 cover imitations and treatments. softcover. Minerals and rocks that look like jade include more than a dozen varieties (e.g. , , etc.). Many treatments are performed on jade, including waxing, heating, coating and polymer impregnation, among others. These chapters provide a well-researched discussion of these aspects. Chapter 6 offers a discussion of price factors for jadeite and nephrite, including colour, clarity, cutting style/shape, cut quality, carat weight or stone size, This book is the fourth in a series covering exotic transparency, treatment status and texture. Figure and unusual gems by Renee Newman that explores 6.1 shows a magnificent jadeite ring that sold for their history, lore, evaluation, geographic sources and US$101,400 at Sotheby’s in 2004. (Reviewer’s note: identifying properties. I find these books very readable Today it could be valued at perhaps more than 10 and highly recommend all of them. times this amount.) Newman mentions that the highest In this Volume 4, Jade & Abalone Pearls, a quick auction price for a piece of jadeite jewellery was perusal of the table of contents shows 12 chapters attained in 2014 (US$27,440,000 for a sold by (116 pages) that are devoted to jade. The final, 13th, Sotheby’s Hong Kong); China was the driving force. chapter dedicates 13 pages to understanding abalone Several other notable auction pieces are described and pearls. pictured in detail. In this chapter Newman includes the Well-written books on jade in the English Mason-Kay ‘Colors of Jade’ chart (Figure 6.8), which language are rare. The advantages of this book are is one of my personal favourites and was nice to see that it is inexpensive, understandable and extensively reproduced here. researched. Newman provides answers to most Chapters 7 through 12 cover various sources of questions that a person with about gemstones jade—both nephrite and jadeite—including China, might have. All of the chapters are well illustrated with Myanmar (Burma), Guatemala, Canada, USA and numerous photographs depicting the corresponding other sources. All of these chapters provide interesting content. Newman also uses tables effectively to reading and anecdotes relating to these various jade illustrate various gemmological points. localities. The first chapter, ‘Why Is Jade so Prized?’, briefly Chapter 13 on abalone pearls gives a brief history covers what makes jade special, with sections titled of various localities, especially concentrating on North Durability, Carvability, Color Palette, Auditive Quality, America, including Baja California (Mexico), and Luster, Rarity, Status Symbol, Therapeutic Virtues, California and Oregon (USA). Paˉua abalone mabe Historical Significance, Investment Appreciation pearl cultivation is briefly mentioned. Identification, Potential and Spiritual & Mystical Significance. pricing and care are also discussed. Numerous Newman covers these attributes in just four pages, photographs accompany the abalone pearl chapter. but the reader can find more detailed explanations The book ends with a bibliography and an index. of some of them in the following chapters. Chapter 2 William F. Larson answers the question ‘What Is Jade?’ and is followed Palagems.com, Fallbrook, California, USA

82 The Journal of Gemmology, 35(1), 2016 New Media

Gems & Crystals: From One of the World’s Great Collections

By George E. Harlow and on garnets, for instance, treats ‘malaia’ as the Anna S. Sofianides, 2015. latest variety, although since then spessartine from Sterling, New York, New Namibia, grandite garnets from Mali and mint-green York, USA, 232 pages, grossular from Tanzania have been discovered. The ISBN 978-1454917113. garnet section also starts with the old adage that US$27.95 hardcover. garnets “come in every colour except blue”, ignoring the relatively recent production of colour-change garnets that can vary with different illumination from purplish red to violetish blue, blue and greenish blue. A second example of outdated information is the pearl section’s omission of the tremendous The first edition of this lovely picture book was availability of Chinese freshwater tissue-nucleated published in 1990. The 2015 edition has been cultured pearls, which are now ubiquitous. Also, the updated in several, but alas not all, subjects. range of colour-treated cultured pearls is much larger From One of the World’s Great Collections than before, and the flamboyantly iridescent abalone in the title refers to the American Museum of pearls are not mentioned. Perhaps the AMNH does Natural History (AMNH) in New York City, USA, not yet have excellent yet representative examples of which indeed has a great collection with a storied these missing gem materials. history. Names such as Dr G. F. Kunz, J. P. Morgan The authors also indicate that is and Tiffany & Co. are associated with its early extremely rare, although in the past few decades, development; later mineral and gem curators fine and commercial have been about included Herbert Whitlock, Dr Vincent Manson as available in jewellery stores as rubies, emeralds and Dr George Harlow, the present curator and an and sapphires. (Admittedly, this trend may not be author of this book. Thus the history given in the permanent, as commercially important deposits of book is rather parochial to the AMNH. tanzanite are known from only a single source.) Part One describes what a gem is, first from a Another problem with this book concerns the historical basis and then in terms of its mineralogy colour reproduction of some of the photographs. and desirable properties. The ‘meat’ of the book This is particularly the case for some green gems is found in Part Two, titled ‘Gallery of Gems and (e.g. , serpentine imitation of jade) and for Crystals’, in which each important gem material is the carved rose quartz Fu dog on page 134. Also discussed either alone (e.g. diamond, topaz, opal) in some figure captions for images containing more or in combination with similar materials (e.g. than one gem variety, it is not clear which stone is chrysoberyl with spinel, group minerals and which material (e.g. the and other gems garnet group minerals). on page 145). For each gem material, the description is A last (mineralogical) criticism of this book is subdivided into data, properties, historical notes, that the title is perhaps misleading. The AMNH has legends and lore, occurrences, materials that could many excellent crystals, but with a few exceptions be confused for the gem, evaluation criteria and, of (e.g. amazonite), the only crystals shown are gemmy course, is accompanied by beautiful pictures. The transparent examples of gem mineral crystals. Should emphasis on history and especially lore is traditional the book instead be titled Gems & Gemmy Gem for the AMNH, hearkening back to Kunz’s interests. Mineral Crystals? Although the scientific data are generally error-free, it These issues aside, this is a very good book for would have been helpful if the authors had included understanding the stories and science behind gems, a separate section on synthesis and gem treatments and for appreciating their incredible beauty. It is for each material, as this information is often critical especially recommended for anyone who does not in determining a gem’s value. have the 1990 edition. Unfortunately, the information in this book is Dr Mary L. Johnson dated with regard to recent finds and changes in Mary Johnson Consulting the availability of some gem materials. The section San Diego, California, USA

New Media 83 New Media

OTHER BOOK TITLES*

Diamonds Medieval Jewelry and Burial Assemblages in (East Central and Eastern Europe in The Global Diamond Industry: Economics and the , 450–1450) Development, Vol. I Ed. by Roman Grynberg and Letsema Mbayi, 2015. By Vladimir Sokol, 2015. Brill, Leiden, The Nether- Palgrave Macmillan, Hampshire, 288 pages, ISBN lands, 268 pages, ISBN 978-900418553. £92.00 978-1137537577. £75.00 hardcover or £75.00 Kindle softcover. edition. Mineral Collections in Austria The Global Diamond Industry: Economics and By Thomas Weiland, 2015. Mineralogical Record Inc., Development, Vol. II Tucson, Arizona, USA, 96 pages. US$15.00 softcover. Ed. by Roman Grynberg and Letsema Mbayi, 2015. Minerals: Their Constitution and Origin, Palgrave Macmillan, Hampshire, 320 pages, ISBN 978-1137537607. £75.00 hardcover or £75.00 Kindle 2nd edn. edition. By Hans-Rudolf Wenk and Andrey Bulakh, 2016. Cambridge University Press, Cambridge, 620 pages, Rough Diamonds, a Practical Guide, 2nd edn. ISBN 978-1107514041. £49.99 softcover, £95.00 By Nizam Peters, 2015. American Institute of hardcover or £47.49 Kindle edition. Diamond Cutting, Deerfield Beach, Florida, USA, 274 pages, ISBN 978-0966585490. US$165.00 hardcover. Moore’s Compendium of Mineral Discoveries 1960–2015, Vols. I and II Gem Localities By Thomas P. Moore, 2016. Mineralogical Record Inc., Tucson, Arizona, USA, 1,644 pages. US$399.00 Minerals of Ohio, 2nd edn. hardcover. By Ernest H. Carlson, 2015. Ohio Department of Natural Resources Division of Geological Survey The Munich Show/Mineralientage München: Bulletin 69, Columbus, Ohio, USA, 290 pages. US$30 Theme Book Precious Stones hardcover. Ed. by The Munich Show, 2016. Wachholtz Verlag Minerals of Georgia: Their Properties and GmbH, 216 pages, ISBN 978-3529054617. €28.00 Occurrences hardcover. By Julian Gray and Robert Cook, 2016. University of Georgia Press, Athens, Georgia, USA, 344 pages, Jewellery and Objets d’Art ISBN 978-0820345581. US$32.95 flexibound. Art as Adornment: The Life and Work of New York Rocks & Minerals: A Field Guide to Arthur George Smith the Empire State By Dan R. Lynch and Bob Lynch, 2016. Adventure By Charles L. Russell, 2015. Outskirts Press, Parker, Publications, Cambridge, Minnesota, USA, 264 pages, Colorado, USA, 264 pages, ISBN 978-1478744788. ISBN 978-1591935247. US$14.95 softcover. US$64.95 hardcover or US$56.95 softcover. Asia Imagined: In the Baur and Cartier General Reference Collections The Collector and His Legacy: Irénée du By Estelle Niklès van Osselt, 2016. Yale University Pont and the Mineralogical Collection of the Press, New Haven, Connecticut, USA, 368 pages, University of Delaware ISBN 978-8874397228. US$90.00 hardcover. By Sharon Fitzgerald, 2015. Mineralogical Record Cartier Dazzling: High Jewelry and Inc., Tucson, Arizona, USA, 96 pages. US$15.00 Precious Objects softcover. By François Chaille, 2016. Flammarion, Paris, France, Gold: Nature and Culture 272 pages, ISBN 978-2080202604. €95.00 hardcover. By Rebecca Zorach and Michael W. Phillips Jr., 2016. Reaktion Books, Edinburgh, Scotland, 224 pages, Pamela Love: Muses and Manifestations ISBN 978-1780235776. £14.95 softcover. By Pamela Love and Francesco Clemente, 2016. Rizzoli, New York, New York, USA, 176 pages, ISBN * Compiled by Georgina Brown and Brendan Laurs 978-0847848195. US$45.00 hardcover.

84 The Journal of Gemmology, 35(1), 2016

Literature of Interest

Coloured Stones Canadian Mineralogist, 53(3), 2015, 497–510, http:// dx.doi.org/10.3749/canmin.1400107. Blue minerals: Exploring cause & effect. E.A. Skalwold and W.A. Bassett, Rocks & Minerals, 91(1), Nano-structure of the and tridymite 2016, 61–77, http://dx.doi.org/10.1080/00357529.201 stacking sequences in the common purple 6.1099136. opal from the Gevrekseydi deposit, Seyitömer- Kütahya, Turkey. M. Hatipoğlu, Y. Kibici, G. Bumble bee ‘jasper’. H. Serras-Herman, Yanık, C. Özkul and Y. Yardımcı, Oriental Journal Gems&Jewellery, 24(6), 2015, 26–28. of Chemistry, 31(1), 2015, 35–49, http://dx.doi. Chemistry of opal from Ethiopia. H. Ren and L. org/10.13005/ojc/310104.* Li, Journal of Gems & Gemmology, 17(4), 2015, 23–28 (in Chinese with English abstract). isotopic composition as an indicator of ruby and sapphire origin: A review of Russian Colorimetric analysis of green jadeite. D.J. Nie, occurrences. S.V. Vysotskiy, V.P. Nechaev, A.Yu. Y. Zou and X.K. Zhu, in P. Chen (Ed.), Material Kissin, V.V. Yakovenko, A.V. Ignat’ev, T.A. Velivet- Science and Engineering, Proceedings of the 3rd skaya, F.L. Sutherland and A.I. Agoshkov, Ore Annual 2015 International Conference on Material Geology Reviews, 68, 2015, 164–170, http://dx.doi. Science and Engineering, CRC Press/Balkema, org/10.1016/j.oregeorev.2015.01.018. Leiden, The Netherlands, 2016, 411–414, http:// dx.doi.org/10.1201/b21118-87. Quartz: A bull’s eye on optical activity. E.A. Skalwold and W.A. Bassett, 2015, 16 pages, www. Fire . T. Dodge, Gems&Jewellery, 25(1), minsocam.org/msa/OpenAccess_publications/ 2016, 19–21. Skalwold/Quartz_Bullseye_on_Optical_Activity.* Gemmological characteristic [sic] of Pretty padparadscha. R.W. Hughes, InColor, 30, from Jiaohe, Jilin Province. J. Gu, Q. Zhao, J. Lai, 2016, 30-40. C. Wang and Z. Yin, Journal of Gems & Gemmology, 17(5), 2015, 24–31 (in Chinese with English abstract). Raman spectra, morphology and color of beryl. Gemmological characteristic [sic] of ruby and S. Dencheva and K. Bogdanov, Geosciences 2015, sapphire from Muling, Heilongjiang Province. 10–11 December 2015, Sofia, Bulgaria, 15–16, http:// Y. Liu and T. Chen, Journal of Gems & Gemmology, tinyurl.com/jzwk8df.* 17(4), 2015, 1–7 (in Chinese with English abstract). Source constraints on turquoise of the Erlitou The history and occurrence of ‘Buxton site by infrared spectra. J. Ren, X. Ye, Y. Wang, diamonds’. R. Starkey and J. Faithfull, Journal of the S. Luo and G. Shi, Spectroscopy and Spectral Analysis, Russell Society, 18, 2015, 24–45. 35(10), 2015, 2627–2772 (in Chinese with English abstract). The Hope Chrysoberyl. A. Hart, Gems&Jewellery, 25(1), 2016, 22. Tsavorite: Discovery of green -chrome grossular and its market situation analysis. Hope, Hertz and a red spinel. J. Ogden, Z. Li, S. Zhao, Z. Qiu, L. Li and X. Jin, Journal of Gems&Jewellery, 24(6), 2015, 20–21. Gems & Gemmology, 17(4), 2015, 37–48 (in Chinese 3+ Influence of impurities on Cr luminescence with English abstract). properties in Brazilian emerald and alexandrite. N. Ollier, Y. Fuchs, O. Cavani, A.H. Horn and U.S. state gemstones that are blue. M.I. Jacobson, S. Rossano, European Journal of Mineralogy, Rocks & Minerals, 91(1), 2016, 36–47, http://dx.doi.org/ 27(6), 2015, 783–792, http://dx.doi.org/10.1127/ 10.1080/00357529.2016.1099132. ejm/2015/0027-2484. Value factors, design, and cut quality of colored Les jades, lapidaireries comparatives [The jades, gemstones (non-diamond) [Parts 1 and 2]. lapidary comparisons]. E. Gonthier and I.-A. A. Gilbertson, GemGuide, 35(1), 2016, 2–13. Gonthier, Revue de Gemmologie A.F.G., 194, 2015, Value factors, design, and cut quality of colored 17–28. gemstones (non-diamond) [Parts 3 and 4]. Long-range and short-range order in gem A. Gilbertson, GemGuide, 35(2), 2016, 2–11. pargasite from Myanmar: Crystal-structure Vanadium- and chromium-bearing pink pyrope refinement and infrared spectroscopy. garnet: Characterization and quantitative D. Heaveysege, Y.A. Abdu and F.C. Hawthorne, colorimetric analysis. Z. Sun, A.C. Palke and N. Renfro, Gems & Gemology, 51(4), 2015, 348–369, * Article freely available for download, as of press time http://dx.doi.org/10.5741/GemS.51.4.348.*

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